Since you mention you are going to play in a church, one wonders if it is intended as part of the christian cult. If so, you should be very selective, choosing better religious or christian music. If not, go ahead with the excelent suggestions above.For common listeners any classical piece works well as a religious piece. But of course it's a mistake. Once an invited pianist played wonderfully Fur Elise, in our Sunday's cult, but to me such a cute piece was quite out of place.
The Goldberg Variations