Ashton, Gardner and Dyke were famous for The Resurrection Shuffle and had connections with George Harrison and Jon Lord.
Bob Dylan has made a Christian music album, although I understand he reverted to Judaism. There is also Norman Greenbaum's Spirit in the Sky.
Ken Tamplin has been involved in Christian music and worked with Geezer Butler.
Jon Anderson uses Christian references in Yes various tracks, although the context is confusing (Close to the Edge, Holy Lamb).
ELP recorded a dynamic version of Parry and Blake's Jerusalem on Brain Salad Surgery. Many British progressive rock bands had an Anglican Protestant element from the church music they were brought up to hear, sing and play.
Cliff Richard, currently recording his 100th album of new material (according to today's TV news) was openly Christian when it was unfashionable to do so. He appears to have had some recent grizzly plastic surgery too. Philip Bailey lead singer with Earth, Wind and Fire, similarly divides his music.
Stryper made Christian music fashionable in the eighties, because they were good.
Cat Stevens started with Christian (Catholic) music, switched to Budhism and then Islam.
Tony McPhee recorded Amazing Grace for Who Will Save the World? . . . The Mighty Groundhogs.
Quintessence were a Hari Krishna band, not Christian, but I mention them anyway because they are great.