Read up between the difference in dogma, and doctrine because it seems like you have a whole lot to learn about the Church.
I’m no expert, but the essay I read which pointed that out was written by one of the advisers to Vatican II, and who is a noted theological writer. It was published by the department of religious studies, I think by a Catholic university.
So before you tell me what I need to learn about the Church, you may want to do some research yourself. I can post 700 years of papal statements advising the persecution of Jews, but that would not be on topic here.
One of the apparent challenges here, seems to be that people take at face value what Church officials say, today, and neglect to consider the long history of the Church. Nobody today, can tell you what teachings the Church will or will not change tomorrow.
As for dogma and doctrine, money lending is prohibited in the Bible. We all know that, and the Church once took that literally. Now it does not. There are other examples, but that one is indisputable. So, yes, the Church has historically taken literal moral precepts, and changed it’s teachings about what they mean, radically so.
But back to the topic of this post. Asking for non-discrimination in marriage is not about sex. Gays, straights, even priests it seems, have been known to have sex when they want to. And yes, even a pope has been caught having sex with a male. The law does not prohibit consensual sex between adults in most states. In the ones where “sodomy laws” still exist, they would probably be overturned, if tested.
The gay marriage movement is the logical confluence of social and scientific trends in the area of sexuality. Socially, my estimate is that it is a natural result of the women’s rights movement, which sought to eliminate gender discrimination in marriage. This has succeed, which is precisely why the courts are finding that it is illegal to discriminate based on gender for purposes of marriage. It is not rocket science. Scientifically and medically, homosexuality is no longer considered an illness or abnormality. When these two trends are combined, gay marriage makes perfect sense.
We all understand the religious argument, though there are some scholars who would say that the commonly accepted notions of homosexuality held by the men who wrote the Bible were not what we know sexuality to be today. Further, there are scholars who would also say that the sections of the Bible taken to condemn homosexuality have been mistranslated. So, it is not exactly a slam dunk in religious terms either.