Well, FWIW, going to a meeting doesn't COMMIT you to anything. You can go check it out, and decide for yourself if it feels helpful or not. We usually suggest trying six meetings, just because each group is a little different in makeup and format.
The fact that groups meet in churches means absolutely nothing. Al-Anon (like AA) has no affiliation with outside groups, including churches. Churches traditionally offer meeting space to recovery groups (who pay rent to the churches--and it's affordable), so many groups rent their meeting space in churches.
Al-Anon is also not religious--although there is a spiritual component. You will hear God mentioned, and prayer, but I know many agnostics and atheists who comfortably recover in AA and Al-Anon. Many people think of the power of the universe as their Higher Power. Nobody will try to convert you.
I think it's worth a shot. Most people discover they are happy they went.