• Formative Christianity
• Gnosticism
• Religions of Antiquity
• Formative Islam
• Comparative History of Religions

My main area of research over the years has been Valentinianism, the most important variety of Christian ‘Gnosticism’ in Antiquity. I regard it as a distinct branch of Christianity, founded by Valentinus c. 150 CE and still alive at the end of the fourth century. The Valentinians were condemned as heretics by the theologians of mainstream Christianity.

I have worked extensively on the Coptic manuscripts from Nag Hammadi, which among other things contain several important Valentinian texts, and I am co-editor of the book series Nag Hammadi and Manichaean Studies.

Greco-Roman religion and the history of early Christianity are general research interests that cohere naturally with my specialised research.

Another research interest is Islam, where I have previously worked, among other things, on Sufism. I currently take a special interest in the origins of the Qur’an and its Late Antique context.

Finally I have always taken an interest in comparative issues in the study of religion, both thematic and historical. In this area I am now looking at macro-historical processes in the light of cognitive psychology and the general theory of evolution.

 

Academic article

• Thomassen, Einar (2025). A Source-Critical Translation of the Apocryphon of John (Short Recension). (external link)
• Thomassen, Einar (2022). Protology and Eschatology in Gnostic Thought. (external link)
• Thomassen, Einar (2021). Gnostic Prophecy: The Case of Marcus the Magician and his Women. (external link)
• Thomassen, Einar (2020). The Relative Chronology of the Valentinian Systems. (external link)
• Thomassen, Einar (2020). Were There Valentinian Schools?. (external link)
• Thomassen, Einar (2019). Da religionsvitenskapen kom til Bergen. (external link)
• Thomassen, Einar (2018). To profeter. (external link)
• Thomassen, Einar (2017). The Eucharist in Valentinianism. (external link)
• Thomassen, Einar (2017). Theological and Philosophical Treatises in the Nag Hammadi Codices. (external link)
• Thomassen, Einar (2016). Gnostic Paradises. (external link)
• Thomassen, Einar; Tsakos, Alexandros; Bull, Christian Hervik et al. (2013). A New Edition of the Wizz Codex with an English Translation. (external link)
• Thomassen, Einar (2013). Guder og andre overmenneskelige aktører. (external link)
• Thomassen, Einar (2011). Minnetale over professor Alv Kragerud. (external link)
• Thomassen, Einar (2011). Jakten på gnostiske egg. (external link)
• Thomassen, Einar (2010). Le valentinisme à Nag Hammadi. (external link)
• Thomassen, Einar (2009). Islamic Hell. (external link)
• Thomassen, Einar (2004). The Epiphany of Gnosis. (external link)
• Thomassen, Einar (2004). Orthodoxy and Heresy in Second Century Rome. (external link)
• Thomassen, Einar (2004). Anmeldelse av Ennio Sanzi, I culti orientali nell'impero romano: Un'antologia di fonti. (external link)
• Thomassen, Einar (2004). Anmeldelse av P. Mirecki og M. Meyer (utg.), Magic and Ritual in the Ancient World. (external link)
• Thomassen, Einar (1998). Religionsvitenskap i skolen?. (external link)
• Thomassen, Einar (1998). Teologi og religionshistorie�mot en ny tverrfaglig identitet?. (external link)
• Thomassen, Einar (1997). Satansversene: Fiksjon og fakta. (external link)
• Thomassen, Einar (1995). Spiseritualer blant de første kristne. (external link)
• Thomassen, Einar (1995). L´historie du valentinisme et le Trait#/e tripartite. (external link)
• Thomassen, Einar (1994). Gnostic Semiotics: The Valentinian Notion of the Name. (external link)
• Thomassen, Einar (1994). J. Zandee: The Teachings of Sylvanus. (external link)
• Thomassen, Einar (1994). Exodus 1-15, exempelvis. (external link)
• Thomassen, Einar (1993). Gnostic Semiotics: The Valentinian Notion of the Name. (external link)
• Thomassen, Einar (1992). Målestokken og spanskrøret: Kanon som religionsvitenskapelig term. (external link)

Textbook

• Thomassen, Einar (2023). Jødedom, kristendom, islam: Sammenligninger. (external link)
• Gilhus, Ingvild Sælid; Thomassen, Einar (2010). Oldtidens religioner. Midtøstens og Middelhavsområdets religioner. (external link)
• Thomassen, Einar; Rasmussen, Tarald (2007). Kristendomen : en historisk introduktion. (external link)
• Thomassen, Einar; Rasmussen, Tarald (2002). Kristendommen: En historisk innføring. (external link)
• Thomassen, Einar; Rasmussen, Tarald (2000). Kristendommen: En historisk innføring. (external link)

Academic monograph

• Thomassen, Einar (2023). Before Valentinus: The Gnostics of Irenaeus. (external link)
• Thomassen, Einar (2021). The Coherence of “Gnosticism”. (external link)
• Thomassen, Einar (2006). The spiritual seed : the church of the "Valentinians". (external link)

Encyclopedia article

• Thomassen, Einar (2022). Nag Hammadi. (external link)
• Thomassen, Einar (2020). Melchizedek (NHC IX,1). (external link)
• Thomassen, Einar (2019). Marsanes (NHC X,1). (external link)
• Thomassen, Einar (2016). Hypsiphrone (NHC XI, 4). (external link)
• Thomassen, Einar (2016). Interpretation of Knowledge, The (NHC XI,1). (external link)
• Thomassen, Einar (2016). Holy Book of the Invisible Spirit, The (NHC III,2; IV,2). (external link)
• Thomassen, Einar (2016). Bridal Chamber. (external link)
• Thomassen, Einar (2016). Johannine Literature. (external link)
• Thomassen, Einar (2016). Sophia. (external link)
• Thomassen, Einar (2015). Gnosis, Gnosticism, I General. (external link)
• Thomassen, Einar (2015). Gnosis, Gnosticism, II Gnosis and New Testament. (external link)
• Thomassen, Einar (2015). Gnosis, Gnosticism, VI.A Patristic and Orthodox Churches. (external link)
• Thomassen, Einar (2015). Gospel of Truth, The (NHC I,3; XII,2). (external link)
• Thomassen, Einar (2014). Eugnostos the Blessed (NHC III,3; V,1). (external link)
• Thomassen, Einar (2014). Exegesis on the Soul, The (NHC II,6). (external link)
• Thomassen, Einar (2013). Discourse on the Eighth and Ninth, The (NHC VI,6). (external link)
• Thomassen, Einar (2013). Dialogue of the Saviour, The (NHC III,5). (external link)
• Thomassen, Einar (2012). Concept of Our Great Power (NHC VI,4). (external link)
• Thomassen, Einar (2011). Barbelo-Gnostics. (external link)
• Thomassen, Einar (2011). Authoritative Teaching (NHC VI,3). (external link)
• Thomassen, Einar (2009). Archon/Archons. II. Christianity. (external link)
• Thomassen, Einar (2009). Allogenes (NHC XI,3). (external link)
• Thomassen, Einar (2009). Adam, The Apocalypse of (NHC V,5). (external link)
• Thomassen, Einar (2009). Asclepius (NHC VI,8. (external link)

Book review

• Thomassen, Einar (2022). Review of Joseph Verheyden, Jens Schröter, and Tobias Nicklas (ed.), Texts in Context: Essays on Dating and Contextualising Christian Writings from the Second and Early Third Centuries (Bibliotheca Ephemeridum Theologicarum Lovaniensium 319; Peeters; 2021). (external link)
• Thomassen, Einar (2022). Sarah-Magdalena Kingreen, Tertullians Schrift Adversus Valentinianos. (external link)
• Thomassen, Einar (2020). Anmeldelse av Bjørn Are Davidsen, Lurt av læreboken? Feil og forvirring om kristen tro i læremidlene.. (external link)
• Thomassen, Einar (2019). Review of Exposé du mythe valentinien et textes liturgiques (NH XI,2). By Wolf-Peter Funk and Jean-Pierre Mahé. Québec/Louvain 2016.. (external link)
• Thomassen, Einar (2018). The Qur’an: A New Annotated Translation. By Arthur J. Droge.. (external link)
• Thomassen, Einar (2015). Anmeldelse av Kristin Brandtsegg Johansen, Maria Magdalena: Disippelen Jesus elsket. (external link)
• Thomassen, Einar (2014). Anmeldelse av Bart D. Ehrman, Forgery and Counterforgery. (external link)
• Thomassen, Einar (2013). Anmeldelse av Jan N. Bremmer, The Rise of Christianity through the Eyes of Gibbon, Harnack and Rodney Stark. (external link)
• Thomassen, Einar (2011). Anmeldelse av M. Ziegler, Successio. Die Vorsteher der stadrömischen Christengemeinde in den ersten beiden Jahrhunderten. (external link)
• Thomassen, Einar (2011). Anmeldelse av Uwe-Karsten Plisch, Das Thomasevangelium. Originaltext mit Kommentar (Stuttgart 2007). (external link)
• Thomassen, Einar (2010). Anmeldelse av Barbara Aland, Was ist Gnosis?. (external link)
• Thomassen, Einar (2010). Anmeldelse av Anders-Christian Jacobsen (ed.), The Discursive Fight over Religious Texts in Antiquity. (external link)
• Thomassen, Einar (2010). Anmeldelse av Ismo Dunderberg, Beyond Gnosticism: Myth, Lifestyle, and Society in the School of Valentinus. (external link)
• Stausberg, Michael; Thomassen, Einar; Cavallin, Clemens et al. (2008). Anmeldelse Arne Bugge Amundsen (red.), Norges religionshistorie, Universitetsforlaget, Oslo, 2005. (external link)
• Thomassen, Einar (2002). Moskeer i Norge. (external link)

Academic chapter/article/Conference paper

• Thomassen, Einar (2021). Widengren, Gnosticism, and the Religionsgeschichtliche Schule. (external link)
• Thomassen, Einar (2021). Was there a distinct Gnostic Book Culture?. (external link)
• Thomassen, Einar (2021). Philology. (external link)
• Thomassen, Einar (2019). Valentinus and the Valentinians. (external link)
• Thomassen, Einar (2019). There Is No Such Thing as Gnosticism: But What Have We Got Instead?. (external link)
• Thomassen, Einar (2018). Saving Letter, Saving Book: The Hymn of the Pearl, the 23rd Ode of Solomon and the Gospel of Truth. (external link)
• Thomassen, Einar (2018). The rhetorical construction of heresy in the Church Fathers. (external link)
• Thomassen, Einar (2018). Temple and Sacerdotal Imagery in Valentinian Gnosticism. (external link)
• Thomassen, Einar (2018). A ‘Sayings Gospel’ attested at Nag Hammadi. (external link)
• Thomassen, Einar (2018). Valentinus und der Valentinianismus. (external link)
• Thomassen, Einar (2018). Mani und der Manichäismus. (external link)
• Thomassen, Einar (2018). Sethianismus. (external link)
• Thomassen, Einar (2018). Bardesanes (Bardaisan) von Edessa. (external link)
• Thomassen, Einar (2018). Basileides und seine Anhänger. (external link)
• Thomassen, Einar (2018). Überblick. (external link)
• Thomassen, Einar (2017). The Melothesia of the Apocryphon of John and the Umm al-kitāb. (external link)
• Thomassen, Einar (2017). Gnosis and Philosophy in Competition. (external link)
• Thomassen, Einar (2016). What Is a “God” Actually?: Some Comparative Reflections. (external link)
• Thomassen, Einar (2015). Filologiens videnskabelighet. (external link)
• Thomassen, Einar (2013). Ikke bare Bibelen: Hellige skrifter i antikken. (external link)
• Thomassen, Einar (2013). Saved by nature? The question of human races and soteriological determinism in Valentinianism. (external link)
• Thomassen, Einar (2013). Going to Church With the Valentinians. (external link)
• Thomassen, Einar (2013). Sethian Names in Magical Texts: Protophanes and Meirotheos. (external link)
• Thomassen, Einar (2013). The Valentinian Materials in James (NHC V,3 and CT,2). (external link)
• Thomassen, Einar (2012). What is Heresy, and Why Did it Matter?. (external link)
• Thomassen, Einar (2012). Egypt som paradiset. (external link)
• Thomassen, Einar (2011). Philology. (external link)
• Thomassen, Einar (2011). Baptism among the Valentinians. (external link)
• Thomassen, Einar; Suciu, Alin (2011). An Unknown ‘Apocryphal’ Text from the White Monastery. (external link)
• Thomassen, Einar (2010). Le valentinisme à Nag Hammadi. (external link)
• Thomassen, Einar (2010). Heracleon. (external link)
• Thomassen, Einar (2010). Some Notes on the Development of Christian Ideas about a Canon. (external link)
• Thomassen, Einar (2010). Orphics and Gnostics. (external link)
• Thomassen, Einar (2009). Dialogues with the Archons: The Post-mortem Encounters of the Ascending Soul in Gnostic Texts. (external link)
• Thomassen, Einar (2009). Valentinian ideas about salvation as transformation. (external link)
• Thomassen, Einar (2009). Jesus in the New Testament Apocrypha. (external link)
• Thomassen, Einar (2008). Kilder og arbejdsredskaper til studiet af gnosticismen. (external link)
• Thomassen, Einar (2008). Is Judas really the Hero of the Gospel of Judas?. (external link)
• Thomassen, Einar (2008). Judasevangeliet og gnosticismen. (external link)
• Thomassen, Einar (2008). Kjetteri i middelalderen: katarene. (external link)
• Thomassen, Einar (2008). Kjetteribegrepets opprinnelse og de første kjetterne. (external link)
• Thomassen, Einar (2007). Tekstkritikk og kanon. (external link)
• Thomassen, Einar (2007). From Wisdom to Gnosis. (external link)
• Thomassen, Einar (2007). “Forgery” in the New Testament. (external link)
• Thomassen, Einar; Pasquier, Anne (2007). L’Évangile de la vérité (NH I, 3; XII, 2). (external link)
• Thomassen, Einar (2007). IV. Les écrits valentiniens de Nag Hammadi. (external link)
• Thomassen, Einar; Painchaud, Louis (2007). Traité tripartite (NH I, 5). (external link)
• Thomassen, Einar; Painchaud, Louis (2007). Interprétation de la gnose (NH XI, 1). (external link)
• Thomassen, Einar (2007). Den gnostiske reisen. (external link)
• Thomassen, Einar (2007). The Valentinian School of Gnostic Thought. (external link)
• Thomassen, Einar (2007). The Gospel of Truth. (external link)
• Thomassen, Einar (2007). The Treatise on Resurrection. (external link)
• Thomassen, Einar (2007). Forord. (external link)
• Thomassen, Einar (2007). The Tripartite Tractate. (external link)
• Thomassen, Einar (2007). The Interpretation of Knowledge. (external link)
• Thomassen, Einar (2006). Hva enhver student i religionsvitenskap trnger å vite om filologi. (external link)
• Thomassen, Einar (2006). Religious Education in a Pluralistic Society: Experiences from Norway. (external link)
• Thomassen, Einar (2006). Gos. Philip 67:27–30: not “in a mystery”. (external link)
• Thomassen, Einar (2006). The Reception of Greco-Roman Religious and Cultic Terminology in Judaism and Christianity, with Special Reference to Sacrificial Terminology. (external link)
• Thomassen, Einar (2004). Musings on 'Syncretism'. (external link)
• Thomassen, Einar (2004). Sacrifice: Ritual murder or dinner party?. (external link)
• Thomassen, Einar (2003). Becoming a different person: Baptism as an initiation ritual. (external link)
• Thomassen, Einar (2003). Das norwegische Experiment mit Religionsunterricht für alle. (external link)
• Thomassen, Einar (2002). "Jesu hemmelige ord: Thomasevangeliet og andre apokryfe evangelier". (external link)
• Thomassen, Einar (2001). Et gnostisk syn på oppstandelsen. (external link)
• Thomassen, Einar (2000). Wilhelm Schencke—Norway’s First Professor in History of Religions. (external link)
• Thomassen, Einar (2000). The Derivation of Matter in Monistic Gnosticism. (external link)
• Thomassen, Einar; Rasmussen, Tarald (1999). Humanismen. (external link)
• Thomassen, Einar (1999). Islam. (external link)
• Thomassen, Einar (1999). "Is Philology Relevant?". (external link)
• Thomassen, Einar (1999). "Is Magic a Subclass of Ritual?". (external link)
• Thomassen, Einar (1998). Moskérommet. (external link)
• Thomassen, Einar (1997). How Valentinian is The Gospel of Philip?. (external link)
• Thomassen, Einar (1996). "Welcoming a New Department". (external link)
• Thomassen, Einar (1995). Logos apo siges proelthon (Ignatius, Mag. 8:2). (external link)
• Thomassen, Einar (1995). Ortodoksi og heterodoksi i det andre århundrets Roma. (external link)
• Thomassen, Einar (1995). Notes pour la d#/elimitation d'un corpus valentinien #`a Nag Hammadi. (external link)
• Thomassen, Einar (1993). The Platonic and the Gnostic "Demiurge". (external link)
• OFahey, Rex Seán; Thomassen, Einar (1993). Letters to Makkib, Abd al-Aziz. (external link)

Introduction

• Markschies, Christoph; Thomassen, Einar (2020). Introduction. (external link)

Academic anthology/Conference proceedings

• Markschies, Christoph; Thomassen, Einar (2020). Valentinianism: New Studies. (external link)
• Thomassen, Einar (2010). Canon and Canonicity: The Formation and Use of Scripture. (external link)
• Petersen, Anders Klostergaard; Hyldahl, Jesper; Thomassen, Einar (2008). Mellem venner og fjender : en folkebog om Judasevangeliet, tidlig kristendom og gnosis. (external link)

Popular scientific article

• Thomassen, Einar (2020). Da julen ble til. (external link)
• Thomassen, Einar (2017). 50 år med religionsvitenskap i Bergen. (external link)
• Thomassen, Einar (2008). The Gospel of Judas, or, Is Philology a Science?. (external link)
• Thomassen, Einar (2004). Dualisme på godt og ondt. (external link)
• Thomassen, Einar (2003). Om å tolke Koranen. (external link)

Lecture

• Thomassen, Einar (2018). Islam, kristendom og jødedom: Har de den samme gud?. (external link)
• Thomassen, Einar (2018). Comparing Religions, Comparing Monotheisms. (external link)
• Thomassen, Einar (2017). The Reformation and its role in the world history of religions. (external link)
• Thomassen, Einar (2017). Hellig krig i Koranen og Islam. (external link)
• Thomassen, Einar (2015). Apokryfe juleevangelier. (external link)
• Thomassen, Einar (2015). Barn født utenfor ekteskap i ulike religioner. (external link)
• Thomassen, Einar (2015). Jihad – krig på Guds vei i Koranen og Islam. (external link)
• Thomassen, Einar (2014). Forskjeller mellom kristendommen og islam. (external link)
• Thomassen, Einar (2007). Den kristne kanon: Hvordan ble Det nye testamente satt sammen?. (external link)
• Thomassen, Einar (2006). Hvordan Bibelen ble til. (external link)
• Thomassen, Einar (2005). The Paternal Womb: Valentinian and Neopythagorean ideas about first beginnings. (external link)
• Thomassen, Einar (2002). “Hva er Thomasevangeliet?”. (external link)
• Thomassen, Einar (2001). Zeus and Athena in the Myths of the Gnostics. (external link)
• Thomassen, Einar (2000). Rettroende og kjettere blant Romas kristne i det andre århundret. (external link)
• Thomassen, Einar (1996). Islam som fiendebilde. (external link)
• Thomassen, Einar (1996). "Innføring i Islam.". (external link)
• Thomassen, Einar (1996). "Det nye kristendomsfaget.". (external link)
• Thomassen, Einar (1996). "Islam og menneskerettighetene.". (external link)
• Thomassen, Einar (1996). "Gnostikerne og den tidlige kristendommens historie.". (external link)
• Thomassen, Einar (1996). "Sigmund Mowinckel: An Insider's View.". (external link)
• Thomassen, Einar (1996). "Hvordan myte blir rite.". (external link)
• Thomassen, Einar (1996). "Mosk"/erommet". (external link)
• Thomassen, Einar (1996). Innføring i Islam. (external link)
• Thomassen, Einar (1993). Filologi og hermeneutikk. (external link)
• Thomassen, Einar (1993). Valentin som religionsstifter. (external link)
• Thomassen, Einar (1993). Forskning om gnostisismen i Norden. (external link)
• Thomassen, Einar (1993). Le valentinisme #`a Nag Hammadi. (external link)
• Thomassen, Einar (1993). The Derivation of Matter in Monistic Gnosticism. (external link)
• Thomassen, Einar (1993). Ortodoksi og heterodoksi i det andre århundrets Roma. (external link)

Academic lecture

• Thomassen, Einar (2018). Was there a special Gnostic book culture?. (external link)
• Thomassen, Einar (2017). Protology and Eschatology in Gnostic Thought. (external link)
• Thomassen, Einar (2017). Religion among the Societal Challenges: Opportunities for Research on Religion in the Third Pillar of Horizon 2020. (external link)
• Thomassen, Einar (2017). Asceticism at the Threshold between Christianity and Formative Islam. (external link)
• Thomassen, Einar (2017). Historien om opprettelsen av religionsvitenskap ved UiB. (external link)
• Thomassen, Einar (2017). Canonization and Codification. (external link)
• Thomassen, Einar (2017). Response to Geoff Smith, “Anti-Origenist Redaction in the Fragments of the Gospel of Truth (NHC XII,2).”. (external link)
• Thomassen, Einar (2017). Eusebius on Apollonius: Recasting the boundaries of religion, magic and philosophy (Reply to Hierocles).. (external link)
• Thomassen, Einar (2017). Orphism as a Religion. (external link)
• Thomassen, Einar (2015). Theological and Philosophical Treatises in the Nag Hammadi Codices. (external link)
• Thomassen, Einar (2015). Were there Valentinian Schools?. (external link)
• Thomassen, Einar (2015). The Axial Age and the Question of Islam. (external link)
• Thomassen, Einar (2015). There is no such thing as Gnosticism. But what have we got instead?. (external link)
• Thomassen, Einar (2015). The Emergence of Islam. (external link)
• Thomassen, Einar (2013). The Rhetorical Construction of Heresy in the Church Fathers. (external link)
• Thomassen, Einar (2013). The World of Symbols in Valentinian Gnosticism. (external link)
• Thomassen, Einar (2013). The Relative Chronology of the Valentinian Systems. (external link)
• Thomassen, Einar (2013). "Saved by Nature": Searching for the Right Questions. (external link)
• Thomassen, Einar (2013). Were Gnostics Over-achievers?. (external link)
• Thomassen, Einar (2007). Valentinian ideas about salvation as transformation. (external link)
• Thomassen, Einar (2007). La semence spirituelle. (external link)
• Thomassen, Einar (2007). Islamic Hell. (external link)
• Thomassen, Einar (2007). From life cycle rituals to rituals of initiation. (external link)
• Thomassen, Einar (2006). The Spiritual Seed: Response. (external link)
• Thomassen, Einar (2006). Valentiniansk kristologi og soteriologi - et misforstått kapitel i kirkehistorien. (external link)
• Thomassen, Einar (2006). 1 Mos 1:26-27: den religionshistoriske bakgrunnen. (external link)
• Thomassen, Einar (2006). Is Judas really the hero of the Gospel of Judas?. (external link)
• Thomassen, Einar (2006). Religionsfrihetens grenser i antikken. (external link)
• Thomassen, Einar (2006). Valentinianism: A misunderstood chapter in the history of early Christianity. (external link)
• Thomassen, Einar (2006). The Invention of Heresy. (external link)
• Thomassen, Einar (2005). Tekstkritikk og kanon. (external link)
• Thomassen, Einar (2005). The Reception of Graeco-Roman Religious and Cultic Terminology in Judaism and Christianity with a Special Reference to Sacrificial Terminology. (external link)
• Thomassen, Einar (2005). Gnostic Hell. (external link)
• Thomassen, Einar (2005). Functions of scripture in ancient Christianity. (external link)
• Thomassen, Einar (2005). Imagistic and doctrinal dimensions of Christian Gnostic ritual. (external link)
• Thomassen, Einar (2003). Globalisation in Antiquity: Response. (external link)
• Thomassen, Einar (2003). From Wisdom to Gnosis. (external link)
• Thomassen, Einar (2003). An Unknown Sayings Gospel. (external link)
• Thomassen, Einar (2003). Marcus the Gnostic and female prophetesses. (external link)
• Thomassen, Einar (2002). "Revelation as Book and Book as Revelation: Reflections on the Gospel of Truth.”. (external link)
• Thomassen, Einar (2002). "Who were the Valentinians?". (external link)
• Thomassen, Einar (2002). "The Presence of the Gnostic Revealer". (external link)
• Thomassen, Einar (2002). "Thomasevangeliet og andre apokryfe evangelier". (external link)
• Thomassen, Einar (2002). "Presentasjon av høringsutkastet til ny KRL-plan". (external link)
• Thomassen, Einar (2002). “The Womb of Rebirth”. (external link)
• Thomassen, Einar (2002). Valentinianismen. (external link)
• Thomassen, Einar (2001). Muhammad i skolen. (external link)
• Thomassen, Einar (2001). The epiphany of gnosis. (external link)
• Ulvestad, E; Kanestrøm, A; Madland, TM et al. (2000). Evaluation of diagnostic tests for antinuclear antibodies in rheumatological practice. (external link)
• Thomassen, Einar (2000). Early Christian Initiation: The Valentinian Version. (external link)
• Thomassen, Einar (2000). Orthodoxie et hérésie à Rome au deuxième siècle. (external link)
• Thomassen, Einar (2000). Orthodoxy and Heresy in Second Century Rome. (external link)
• Thomassen, Einar (2000). Orthodoxy and Heresy in Second Century Rome. (external link)
• Thomassen, Einar (2000). Early Christian Initiation and the Theory of Transformation Rituals. (external link)
• Thomassen, Einar (2000). Ancient Christian Baptism as an Initiation Rite. (external link)
• Thomassen, Einar (1999). Is Magic a Subclass of Ritual?. (external link)
• Thomassen, Einar (1997). Is Philology Relevant?. (external link)

Article in business/trade/industry journal

• Thomassen, Einar (2017). Selektiv historieskrivning. (external link)

Programme participation

• Thomassen, Einar (2017). Om nyere Koran-forskning. (external link)
• Thomassen, Einar (2015). Nyoppdaget Koran-håndskrift i Birmingham. (external link)
• Thomassen, Einar (2015). Judas og Judaevangeliet. (external link)
• Thomassen, Einar (2002). Kristendommen i den antikke verden. (external link)

Academic literature review

• Thomassen, Einar (2015). (Review of) J. Rüpke (ed.),The Individual in the Religions of the Ancient Mediterranean. (external link)
• Thomassen, Einar (2014). Are gods really moral monitors? Some comments on Ara Norenzayan’s Big Gods by a historian of religions. (external link)
• Thomassen, Einar (2010). Anmeldelse av Johanna Brankaer/Hans-Gebhadt Bethge, Codex Tchacos: Texte und Analysen. ISBN 978-3-11-019570-5. (external link)

Non-fiction book

• Thomassen, Einar (2011). Manikeiske skrifter. Utvalg og innledende essay av Einar Thomassen; oversatt av Prods Oktor Skjærvø og Einar Thomassen. (external link)
• Thomassen, Einar (2003). Mircea Eliade: Det hellige og det profane, og andre skrifter. (external link)
• Thomassen, Einar; Gilhus, Anne Ingvild S (2002). Gnostiske skrifter. (external link)
• Thomassen, Einar; Moxnes, Halvor (2001). Apokryfe evangelier. (external link)
• Rasmussen, Tarald; Thomassen, Einar (1999). Kildesamling til Kristendomskunnskap med religions- og livssynsorientering; Tilleggshefte. (external link)
• Thomassen, Einar; Rasmussen, Tarald (1999). Kildesamling til Kristendomskunnskap med religions- og livssynsorientering. (external link)
• Thomassen, Einar; Rasmussen, Tarald (1999). Kildesamling til kristendomskunnskap med religions- og livssynsorientering: Tilleggshefte. (external link)
• Jordan, David R.; Montgomery, Hugo; Thomassen, Einar (1999). The world of ancient magic: Papers from the first International Samson Eitrem Seminar at the Norwegian Institute at Athens 4-8 May 1997. (Papers from the Norwegian Institute at Athens 4). (external link)
• Thomassen, Einar; Radtke, Bernd (1993). The Letters of Ahmad ibn Idris. (external link)
• Thomassen, Einar; Radtke, Bernd; Bernd, Radtke (1993). The Letters of Ahmad Ibn Idris. Edited, translated and annotated by Albrecht Hofheinz, Ali Salih Karrar, R.S. 0Fahey, Bernd Radtke and Einar Thomassen. (external link)

Academic commentary

• Thomassen, Einar; Painchaud, Louis; Funk, Wolf-Peter (2010). L’Interprétation de la gnose (NH XI,1). (external link)

Editorial

• Thomassen, Einar (2009). The uses of hell. (external link)

Masters thesis

• Thomassen, Einar; Rognstad, Marius (2007). Gnostiske initiasjonsritualer: En studie av initiasjonsritualene i 2. Jesubok i Codex Brucianus. (external link)
• Thomassen, Einar; Aasland, Helge Line (2007). Konstruksjon av tawhid i politisk islamsk diskurs. (external link)

Feature article

• Thomassen, Einar (2007). Tidsskriftartikkelfetisjismen. (external link)
• Thomassen, Einar (2004). Om skaut og 'islam'. (external link)
• Gravem, Peder; Mogstad, Sverre Dag; Rasmussen, Tarald et al. (2001). Fellesfag i forandring. (external link)
• Thomassen, Einar (1998). Anmeldelse av G. Wurst, Die Bema-Psalmen. (external link)
• Thomassen, Einar (1997). Det misforståtte faget. (external link)
• Thomassen, Einar (1996). "Det nye religiøse Norge.". (external link)
• Thomassen, Einar (1996). Anmeldelse av A. Khosroyev, Die Bibliothek von Nag Hammadi: Einige Probleme des Christentums in Ägypten während der ersten Jahrhunderte. (external link)
• Thomassen, Einar (1996). Anmeldelse av S. Richter, Exegetisch-literarkritische Untersuchungen von Herakleidespsalmen des koptisch-manichäischen Psalmenbuches. (external link)
• Thomassen, Einar (1996). Fire innlegg om religionsvitenskapens fremtid: Innledning. (external link)
• Thomassen, Einar (1993). Omtale av J. Zandee, The Teachings of Sylvanus. (external link)

Interview

• Thomassen, Einar; Nilsen, Marika Muhonen (2002). Nordisk nysgjerrighet i Alexandria. (external link)

Report

• Thomassen, Einar; Jordan, David R.; Montgomery, Hugo (1999). The world of ancient magic: Papers from the first International Samson Eitrem Seminar at the Norwegian Institute at Athens 4-8 May 1997. (Papers from the Norwegian Institute at Athens. (external link)
• Thomassen, Einar (1994). Islam. (external link)

Compendium

• Natvig, Richard; Brochmann, Randi; Dao-Vu, Dominique et al. (1998). Studiehefte: Studierettleiing for fjernundervisningsstudentar i Religionsvitskap delfag. Modul 1. (external link)

See a complete overview of publications in Cristin.

• The coherence of ‘Gnosticism’
• Comparative themes of Judaism, Christianity, and Islam (textbook)
• The Study of Religion (short introduction)
• Topics of formative Islam
• The two versions of the Gospel of Truth