The pop group tunes up. The house lights dim. Into the spotlight steps a young man in a while jacket. The scene for evensong, 1967-style, is set. And, as always. The Rev. Paul Jobson (Church of England) has a full house. Fr. Giarchi, a Roman Catholic priest, enjoys similar success, taking his special brand of religion to the people. In the North they call him the Tommy Cooper of the Church circuit, applauding his slick act performed against a backcloth of pin-ups and pop images. Two clergymen of different denominations, but with similar ideas and ideals: that you've got to have a gimmick to sell anything these days. Some worshippers disagree. Some ministers are incensed by the suggestion. Are the pop preachers selling Christianity or getting in the way of it?