OMG I hope that is a joke or you are being sarcastic. What church would actually call the police on someone..wedding or private event or not. That is sad.
I said "if they were not wanted by the couple," as in, if the couple specifically had a problem with them being there. It's not as though invitations are checked at the door. It's the couple's day and their party, and in our particular church there is no tradition that it must be open to the public. I have no idea why anyone would think the fact that it is a church would mean they cannot call the cops if someone is trespassing.