I suppose whether or not a church will allow non-believers to marry on their premises will depend whether they see themselves as there only to serve committed believers or as an integral part of the wider community they are located in. I wouldn't want to get married in a church personally, but for a lot of people it's a fundamental part of the entire experience. The local CofE church near my house also serves as a venue for (non-religious) live music, a film club, a green festival and a rather good beer festival. Your credentials are not checked on the door. It also organises a fun run (no doubt to "raise money for the church roof", which always sounds like a euphemism) that lots of local people who don't attend the church participate in. Surely being part of your local community and appreciated by local people for that is better than remaining aloof? Certainly it appears to be more in line with the best of JC's teachings...