Remember that people who thought themselves to be Christians slayed thousands of people trying to make those people turn to Christianity. Were those people true Christians? Hell no.
A person has no choice to be born American, or white, or black, or Hispanic, or anything else. No one would choose to have a child born with a disability.
Homosexuality IS a choice. Just as adultery, and promiscuity, and even a consenting man and woman living together sleeping in the same bed. Those are all choices that people make.
Interracial marriage is not a sin, a Christian marrying an unbeliever, that is considered a sin, according to what I know of the Bible. Others believe differently than I do, but we still search the Scriptures for the answers to all kinds of questions, the key is to keep on searching, for Christianity is a learning religion, and as we grow, we learn and we adapt. The basis for our faith is the one true constant. John 3:16, if you have that, and you truly believe that, you will want to learn more.