“The Word-ah ... praise Jesus ... will abide FOR-EVER ... amen,” the preacher pokes his King James with a misshapen finger, punctuating the short, but electrifying sermon before breaking into a hoarse rendition of “I saw the light.”

From behind the pulpit, musicians supply Skynyrdesque accompaniment to the old standard, adding kindling to the flames in the hearts of the congregation who don’t require the…