We always choose times and places when it's comfortable for theists, but they can always retreat into their groupthink. I think we should be on the offensive when they are in their groupthink. We should protest outside of churches, boo them when they are walking to and from their car going there. We should make it HARD to be even a casual believer. Church sucks to go to already, but make it unbearable. We should bang on some doors, insult the parents for forcing their kids to believe as they do. Hold protests outside of a priest's house day and night. Follow the priest, boo him wherever he goes. Grocery store? Boo him as he's leaving his car, debate him in the store, on the way back.
They can't (legally) do anything as long as we don't try to stop them from entering the church. They can go to church, while we protest outside.