My friend Michael Johnston, himself a former homosexual, has observed that homosexuality is contrary to God's model for relationships because it is contrary to His character. So they are no longer two, but one. Therefore what God has joined together, let man not separate. That same model is pictured in the Gospel many times with Jesus as the Bridegroom and His church as the bride. Homosexuality is a spiritual abomination because it perverts this picture.
Biblical marriage affirms it.
Homosexuality is not a special problem in need of a special solution, according to Michael, and I agree. All sexual immorality is rooted in the sinful condition of the human heart. The real solution is not to fix the flesh but to walk in the Spirit, that is, to become more and more like Christ. I understand that, but I'm just trying to explain my position and offer you a thoughtful perspective on the issue with which you might not be familiar. At the same time there is evidence outside the Scripture that homosexual relationships are not normal or natural.