Endsjø er most know for his research on sex and religion, religion and human rights, and on how Greek beliefs in physical immortality and resurrection influenced early Christianity. He also works with various other fields, such as religion and popular culture, religion and politics, religious and place, religion and gender, religious change, Greek religion, Christianity, and the history of the immortality in Western beliefs.
He is among Norway’s most translated academics with books published in thirteen languages, as well as being one of the country’s most prolific scholars in the public sphere with hundreds of more popular articles.
- Professor in the Study of Religion at the University of Oslo 2016-
- Professor in the Study of Religion at the University of Bergen 2006-2017
- Visiting scholar at Duke University 1999, UTS Columbia University 2003, and San Francisco University 2006
- Postdoctoral Fellow in the History of Ideas at the University of Oslo 2005-2006
- Postdoctoral Fellow in the History of Religion at the University of Oslo 2003-2004
- Associate Professor in the Study of Religion at NTNU, Norwegian University of Science and Technology 2003
- Dr.art. in the History of Religion at the University of Oslo 2003