In Rome, he became a professor at the Pontifical Biblical Institute, where he taught Aramaic, paleography, Hebrew and Sacred Scripture. He also taught theology, part-time, at Loyola University Chicago's John Felice Rome Center. He worked as a translator for the Orthodox Churches and Ancient Oriental Churches Division of the Secretariat for Promoting Christian Unity under Cardinal Bea. Thus, Martin became well acquainted with prominent Jewish leaders, such as Rabbi Abraham Heschel, in 1961 and 1962. Martin accompanied Pope Paul VI on a pilgrimage to the Holy Land in January 1964. He resigned his position at the Pontifical Institute in June 1964.