BA, Baylor University, 1960; BD, Southern Baptist Theological Seminary, 1963; MTh, King's College and the School of Oriental and African Studies, University of London, 1965; PhD, Harvard University, 1972; DLitt (Honoris Causa), Kelaniya University, 1999
The Buddhist, Hindu, and other Asian religious traditions, comparative study of religion, comparative religious philosophy, history of religion, theological issues of a religiously plural world, Sanskrit, Pali, Sinhala
History of humankind's religiousness with special reference to Buddhist and Christian studies; missionaries of Colgate University / India, Sri Lanka, Japan, England, China
- In the Company of Friends: Exploring Faith and Understanding with Buddhists and Christians. (Albany, New York: State University of New York Press, 2012.
- On Living Life Well: Echoes of the Words of the Buddha from the Theravada Tradition, ed. (Pariyatti Press, 2010)
- The Religious Heritage of Japan, ed. (Book East, 1999)
- On Understanding Buddhists: Essays on the Theravada Tradition in Sri Lanka (1993)
- Of Human Bondage and Divine Grace: A Global Testimony, ed. (Open Court, 1992)
- Co-author/ translator, The Dhammapada: A New English Translation with the Pali Text . . . (Oxford University Press, 1987, new paperback edition, 1998)
- The Threefold Refuge in the Theravada Buddhist Tradition, ed. (Anima Books, 1982)
- Religiousness in Yoga, co-editor (1980)
- Religiousness in Sri Lanka, ed. (Marga Institute, 1979)
- Dhamma: Western Academic and Sinhalese Buddhist Interpretations - A Study of a Religious Concept (Hokuseido Press, 1978)
- Numerous articles, reviews in professional and theological journals such as The Journal of the American Academy of Religion, Religious Studies, Journal of Japanese Religion, The Eastern Buddhist, The Journal of Church and State; contributions to A Companion to World Philosophies (1998), Modern Sri Lanka: A Society in Transition (1979), Christian Faith in a Religiously Plural World (1978), etc.
- Recipient of the Senior Class of 2012 Award.
- Recipient of several fellowships and scholarships including a Fulbright-Hays Scholarship to Sri Lanka
- Visiting research associate, Shinto Studies, Kokugakuin University, Tokyo, 1973
- Division of Cultural Anthropology, National Museum of Ethnology, Osaka, 1985-1986
- Buddhist Studies, Ryukoku University, Kyoto, 1985-86
- Otani University, Kyoto, 1993
- Wijesekera Memorial Oration, Colombo, 1993