David Ham attended Schreiner Institute in Kerrville, Texas, and subsequently received an A.B. degree from Hardin-Simmons Baptist University in Abilene, Texas. Ordained a Baptist minister, he entered the Southwestern Theological Seminary in Fort Worth, Texas, in 1938, while pastoring Lakenon Baptist Church in Hillsboro and Forreston Baptist Church in Waxahachie. Prior to entering military service in 1942, he also pastored the First Baptist Church in Irene, Texas. He was commissioned a U.S. Army chaplain, serving with the 97th Infantry Division in Europe, where he earned a Silver Star and Bronze Star.