I claim we have two independent pieces of reasonably compelling evidence in favor of Church:

1) Rudy mentions he'll probably be well enough to go to church tomorrow during Chapter 2; Chapter 3 takes place during the night, so Chapter 4 would occur the next day. Thus, it would make a lot of sense if Rudy's dialogue is meant to foreshadow / setup his presence in Chapter 4.

2) If the chess motif continues, this suggests that Chapter 3 would have an antagonist named "Rook", and Chapter 4 would have an antagonist named "Bishop". Obviously it would make sense for an antagonist named "Bishop" to be in a church.