It depends on the dimensions of the church space, just the sanctuary, or the narthex and choir loft, etc. You need to know how many clients might all be on the wireless at the same time. Space your APs far enough apart to cover the entire area you need, ie on walls around the area(?), but do not put your APs right on the metal framework, I-Beams(?), if thats what you're asking about the "studs".
I guess I was wondering about overlapping. For example we currently have 3 unified pro in our worship center area that at most would seat 500. I guess what I asking is, do i need to have an AP wherever there might be 500 people in an area. example Worship center, main lobby etc