Charles W. Slemming was converted in 1919 and served for eleven years in the pastorate, but realized that the Lord had graciously given him the gift of Bible teaching. In 1946 he left local church ministry to join the staff of Bible Testimony Fellowship, which involved traveling throughout Britain conducting weeks of Bible studies. He was later appointed director of BTF. In 1949 he made the first of seven visits to the USA for a Bible teaching tour. During this period he charted every book of the Bible and wrote a commentary entitled The Bible Digest, receiving a doctorate of divinity for his work. In 1974 he was called home to glory.