Probably you are. The questions are 1: Is there any free will, and 2: if there's not, what does that imply for Christians? There are Christians who believe that salvation at least is predestined. Indeed, I am one of those. So to me, the Bible makes it pretty clear then that choice is not the only thing operating here. To an extent, our behavior is only a sign to us regarding other things God is doing. The entire concept is a diffucult one.
I have only ever had the opportunity to talk with one person who was educated about genetics about this subject. He is an atheist and a decidedly liberal fellow. What he told me was that the idea that homosexuality was genetically determined was not only not proven, but probably likely to be a false one. His support for homosexual marriage was on the grounds of civil liberties, and his support for gays joining churches was that he thought it was good medicine for the church and would likely cause further weakening of the church as more and more religious teachings are proven to be to no benefit. Obviously, on a lot of levels, his views and yours will not mesh. But the point about genetics seems to be nearly universally understood on both sides, with I think perhaps on my side that, even if science thought that genetics plus some level of nurture triggers the homosexual tendency totally outside the homosexual's ability to control, I would still argue that the Spirit of God can change anything. Ultimately, it is a lot like the creation argument. I am aware of a lot of difficulties with Creation, but the fact is, if God did it, He did it, and the rest is just a series of mistakes by man. It doesn't mean God lied if the world looks a certain way and men take it to mean certain things, because God never said, "Look for Truth in the fossile of the earth" or some such.
I am not a hard core young earth creationist though. I have at least one question about Genesis that I can not get an answer for either from creationists or atheists having to do with the significance of the 4 rivers mentioned and whether or not they can all be located, and if not, why?
At the root, I simply reserve the right to believe that God can do anything.