I think it's more that people tend to rank sins based on whether or not they might ever commit them, themselves.<quoted text>Does god rank sin according to severity?
Thus, adultery is a much "lesser sin" than being gay since a straight person is very likely to commit adultery, but it is impossible for them to turn gay.
That is why so many Christian denominations allow those who divorce to remarry, despite Jesus' own words against the practice. Christians KNOW they might be in that boat one day, so conveniently soften that particular sin into non-existence, while screaming against gay folks existing, even though Jesus never said a thing abut homosexuality.
I guess it's human nature.