Born James Ahern, he received the name Barnabas upon taking his vows as a Passionist; ordained in 1941; studied at the Catholic University of America, L’École Biblique, and the Pontifical Biblical Institute. Worked on the New American Bible translation sponsored by the Confraternity of Christian Doctrine. Peritus at the Second Vatican Council (1962-65) serving on the Theological Commission and the Secretariat for Christian Unity. Received the Cardinal Spellman Award (1964) for theological achievement from the Catholic Theological Society of America and served as president of the American Catholic Biblical Association (1964). He was consultor to the International Theological Commission (1970-1983), a member of the Pontifical Biblical Commission and the Pontifical Vulgate Commission (1966-1973), and a consultor to the Congregation of Saints (1981-1988). In 1981, the Archbishop of Canterbury bestowed on him the Order of St. Augustine of Canterbury. A member of ARCIC from 1969-1975.