When he gets to his pew and looks round him he sees just that selection of his neighbors whom he has hitherto avoided. You want to lean pretty heavily on those neighbors. Make his mind flit to and fro between an expression like 'the body of Christ' and the actual faces in the next pew. It matters very little, of course, what kind of people that next pew really contains. You may know one of them to be a great warrior on the Enemy's side. No matter. Your patient, thanks to Our Father Below, is a fool. Provided that any of those neighbors sing out of tune, or have boots that squeak, or double chins, or odd clothes, the patient will quite easily believe that their religion must therefore be somehow ridiculous.