He subsequently studied at University College, Cardiff, graduating in 1955 with an honours degree in Hebrew.
He later studied at Memorial College, Brecon (where he began to learn Welsh), and University of Princeton, United States where in 1959 he was awarded the degree of MTh.
On his return to the UK in 1960, he took up the appointment of minister of Castle Street Congregational Church, Tredegar, Monmouthshire.
In 1963 he married, and under the patronage of the London Missionary Society he and his wife travelled to Western Samoa where David was appointed Principal of Malua Theological College, he remained in the position for the next five years.
Subsequently, he was appointed lecturer in Religious Studies at Bradford Training College and he remained there until 1999, when he retired form the position.