Dr. Bob Jr. began preaching while serving as Acting President during his father’s absences. When his father was away, part of Dr. Bob’s responsibility was to preside over or preach at the daily chapel service. He was not a trained theologian, so to prepare for these preaching opportunities, he began reading some of the great works of systematic theology, sermons of the Puritan divines and the sermons of some contemporary preachers. In the mid-1930s, Dr. Bob began preaching regularly in campus chapel services and began to be invited to preach at revivals and young people’s meetings. By the late thirties he was highly sought as a preacher.

Eventually, Dr. Bob’s preaching career took him to every inhabited continent in the world and every state in the union. He preached to millions of people and saw many thousands converted to Christianity.