The so-called “gay Christian” argument has nothing to do with the fact that homosexuality is only mentioned in the Bible a handful of times. This is a layman’s argument espoused by people who are not integrated into the body of Christ. The real “gay Christian” argument is much more complex than that, but for the sake of time, it can be read about here.*
Most anti-gay arguments are based on the idea that the Bible simply condemns all homosexual relationships. The “gay Christian” argument attempts to dismantle the underlying premise of the anti-gay argument – this premise being that the scriptures pertaining to the condemnation of homosexual acts describe monogamous, loving, same-sex relationships.
Leviticus may have been condemning idol worship through the practice of gay orgies and same-sex intercourse with prostitutes, which has nothing to do with monogamous, loving, same-sex relationships.
The story about the men of Sodom and Gomorrah describes gang rape, which has nothing to do with gay sex.
Paul, in the New Testament, was dealing with a culture of pederasty (older men raping young boys), temple worship in the form of same-sex intercourse with prostitutes (like before, in Leviticus) and sexual excess (men in heterosexual marriages having extramarital affairs with other men), which could be to what he was referring in his condemnations of homosexuality.
These are the things I want to say, but don’t.
It’s better to be more heart, and less attack.
*Note that on this site, the other side of the debate is also presented.