MEMPHIS  In the back room of a theater on Beale Street, John Renken, 37, a pastor, recently led a group of young men in prayer.

“Father, we thank you for tonight,” he said. “We pray that we will be a representation of you.”

An hour later, a member of his flock who had bowed his head was now unleashing a torrent of blows on an opponent, and Mr. Renken was offering guidance that was not exactly prayerful.

“Hard punches!” he shouted from the sidelines of a martial arts event called Cage Assault. “Finish the fight! To the head! To the head!”

The young man was a member of a fight team at Xtreme Ministries, a small church near Nashville that doubles as a mixed martial arts academy. Mr. Renken, who founded the church and academy, doubles as the team’s coach. The school’s motto is “Where Feet, Fist and Faith Collide.”