Because most religions have turned their backs on gay people and denounce them, are most gay people atheists? Anon.
No. As I've said many times, the gay community is a very diverse community. Some gay people are religious and others are not. Certainly there are gays and lesbians who were religious in youth and became less religious as they got older, sometimes because -- as you put it -- the doctrines of their religion were anti-gay. Undoubtedly there are gays and lesbians who are agnostic or atheistic for reasons that may have nothing to do with their sexual orientation.
There are religions which are not homophobic, as well as groups for gay members of religious groups that are homophobic. Dignity, a group for gay Catholics -- the Catholic Church is virulently homophobic -- has been around for many years. And there are churches specifically created to be welcoming to gays.
Interestingly enough, religious attitudes are not the only causes of homophobia. There have been atheists and agnostics who are anti-gay, although the most vehemently homophobic groups and individuals seem to come from the religious sector.
Since religious attitudes can influence people, many gay activists feel it would be a good thing to work within religious groups to broaden their perspective on homosexuality. Other activists feel that religious attitudes and the homophobia that often goes with them, should be completely rejected.
It's your call.