His motivating preaching style is largely influenced by his Kenyan background, which brings a fresh perspective to many American institutions. As a student at Asbury, Joseph earned the Philosophy and the Christian apologetics award and the Frank Bateman Stanger award for excellence in preaching. Joseph has a rich, melodious voice that earned him a Masters degree in church music and which makes listening to him in the classroom enjoyable. He has taught at several schools, including Asbury Seminary and Scott Theological College, and is the author of numerous articles and books, including Revisiting God: A Commonsense Approach to Theism. He has also served as a pastor and choral director at Africa Inland Church and lives with his wife, Sophia.