As a child, Deal attended a Presbyterian Church at his mother’s promptings. In high school, after being witnessed to by a Southern Baptist friend, he accepted Jesus and joined the Baptist Church. After attending the University of Texas, where he was president of the Baptist student union, he enrolled in Princeton Theological Seminary and later received his Ph.D. from Emory. While studying at Emory, he met a Catholic friend, who led him deeper into the Catholic tradition. He started meeting with a priest every week for two years and was finally confirmed a Catholic at the Dominican House in Atlanta, where Flannery O’Connor convalesced.