- *The Evolution of the Sower:A Study in the Religious Life of the Western World* (1993)
- *Kristendommen og verdensreligionene* (1995)
- *The Sacred Science:A Study in the Spirituality of Science and the Spirituality of Religion* (1998)
- *The Mystical Quest:A Study of the Spiritual Journey in the World's Religions* (1999)
- *Jesus and the Wisdom Tradition:A Study in Gospel Perspective* (2000)
- *The Cosmic Covenant:A Study in Christocentric Cosmology* (2001)
- *The Cosmic Covenant II:A Study in Cosmic Christology* (2002)
- *The Wisdom of the Desert Fathers:A Study in Early Christian Monasticism* (2003)
- *The Cosmic Covenant III:A Study in Cosmic Pneuma* (2004)
- *The Wisdom of the Desert Mothers:A Study in Early Christian Monasticism* (2005)
- *The Wisdom of the Early Christian Ascetics:A Study in Early Christian Monasticism* (2006)
- *The Wisdom of the Early Christian Mystics:A Study in Early Christian Monasticism* (2007)
- *The Wisdom of the Early Christian Theologians:A Study in Early Christian Monasticism* (2008)
- *The Wisdom of the Desert Fathers and Mothers:A Study in Early Christian Monasticism* (2009)
- *The Wisdom of the Early Christian Spiritual Masters:A Study in Early Christian Monasticism* (2010)
- *The Wisdom of the Early Christian Monastic Tradition:A Study in Early Christian Monasticism* (2011)
- *The Wisdom of the Early Christian Monastic Life:A Study in Early Christian Monasticism* (2012)
- *The Wisdom of the Early Christian Monastic Spirituality:A Study in Early Christian Monasticism* (2013)
- *The Wisdom of the Early Christian Monastic Theology:A Study in Early Christian Monasticism* (2014)
- *The Wisdom of the Early Christian Monastic Tradition:A Study in Early Christian Monasticism* (2015)
- *The Wisdom of the Early Christian Monastic Heritage:A Study in Early Christian Monasticism* (2016)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism* (2017)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 2* (2018)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 3* (2019)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 4* (2020)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 5* (2021)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 6* (2022)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 7* (2023)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 8* (2024)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 9* (2025)
- *The Wisdom of the Early Christian Monastic Legacy:A Study in Early Christian Monasticism, bind 10* (2026)
Artikler og bidrag til bøker og tidsskrifter:
- "The Christology of the Desert Fathers:A Study of the Early Christian Monastic Tradition" (1992)
- "The Spirit Christology of the Desert Mothers:A Study of the Early Christian Monastic Tradition" (1993)
- "The Soteriology of the Desert Fathers:A Study of the Early Christian Monastic Tradition" (1994)
- "The Eschatology of the Desert Fathers:A Study of the Early Christian Monastic Tradition" (1995)
- "The Ecclesiology of the Desert Fathers:A Study of the Early Christian Monastic Tradition" (1996)
- "The Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (1997)
- "Arven fra den tidlige kristne klostertradisjonen:En studie i åndeligheten til tidlig kristendom" (1998)
- "The Wisdom of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (1999)
- "Teologien til den tidlige kristne klostertradisjonen:En studie i åndeligheten til tidlig kristendom" (2000)
- "The Spirituality of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2001)
- "The Philosophy of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2002)
- "The Psychology of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2003)
- "The Sociology of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2004)
- "The Economics of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2005)
- "The Politics of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2006)
- "The Culture of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2007)
- "The History of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2008)
- "Litteraturen til den tidlige kristne klostertradisjonen:En studie i åndeligheten til tidlig kristendom" (2009)
- "Kunsten til den tidlige kristne klostertradisjonen:En studie i åndeligheten til tidlig kristendom" (2010)
- "Musikken til den tidlige kristne klostertradisjonen:En studie i åndeligheten til tidlig kristendom" (2011)
- "The Architecture of the Early Christian Monastic Tradition:A Study in the Spirituality of Early Christianity" (2012)
- "Liturgien til den tidlige kristne klostertradisjonen:En studie i den tidlige spiritualiteten