We hard-pressed to find a better missiologist in our day than Andrew Walls. Though Walls has not written prolifically, he makes up for it in the profoundity of his work. He has written two landmark books that explore the relationship between history, missions, and theology: The Missionary Movement in Christian History: Studies in Transmission of Faith and The Cross-Cultural Process in Christian History along with a number of articles.
Former missionary to Sierra Leone and Nigeria, Walls later served as director of the Centre for the study of Christianity in the Non-Western world, at the University of Edinburgh. In an article appearing in IBMR 2004, Walls explores the difference between proselytes and converts in the Early Church.