After graduating in 1938 from Lincoln High School in Plymouth, Indiana, Mangun attended Apostolic Bible Institute in St. Paul, Minnesota.

[2] After leaving Bible college, Mangun traveled to the American South, where he held a Christian revival in Lou-Ann, Arkansas.

He next traveled to Diboll, Texas, where he met Vesta Layne Gibson, a preacher's daughter, whom he married on September 10, 1943.

At that time the small church was located at 16th and Day Streets, and was home to a congregation of only thirty-eight adult members.

[5] In September 2004, he was inducted into the United Pentecostal Church International's "Order of the Faith," – a prestigious award honoring him "for outstanding achievement and exemplary service.

[8] Mangun was formerly a chaplain for the Louisiana State Police (Troop E), the Rapides Parish Sheriff’s Department, and the Civil Air Patrol.