 As a professor of the St. Sergius Orthodox Theological Institute (Institut Saint-Serge) he became one of the most highly regarded witnesses to Orthodox Christianity, as well as one of the most prolific.He was a founder of the Orthodox Fellowship in Western Europe, and was the author of thirty books on the life, thought and history of the Orthodox Church, and their meeting with other Christians, the non-Christian religions and modernity.He was responsible for the theological journal, "Contacts", and became a Doctor honoris causa at the Institute for theology in Bucharest and at the Catholic University in Louvain.