There has been nothing sort of a paradigm shift in our thinking regarding homosexuality. In just a few short years, it has not only been acceptable to declare oneself as homosexual, it is celebrated; a prophetic fulfillment of Romans 1:32. This short post will not debate the biblical admonitions against this practice in detail. At this point, you either believe it is wrong or you do not. This battle is lost. The war will be over as the young among us grow older. It is only a matter of time. Few under the age of 25 believe there is anything immoral (they would rarely use that word) about same sex intercourse.
Aside from raising straw-man arguments about how the Old Testament is, well, old, few reference the New Testament. However, this is not another diatribe in that regard either. PRT does not believe that a homosexual cannot be a Christian. The difficulty lies in a person who is an active homosexual. One must understand that whether you believe homosexuals are born the way they are or it is a learned behavior, it is a behavior that must be resisted. Even a cursory reading of our scriptures warns us against many innate inclinations and desires that must be submitted to God's Word. Take for example the single young man. He is a walking bundle of hormones that sees almost every other young woman in a sexual sort of way. He is born this way. And it is learned. Either way, there is little he can do to resist the thoughts that enter his mind. However, he is called by our Lord not to entertain those thoughts and certainly not to act out those thoughts even in a committed relationship until he becomes married. That's it. Nothing more. Nothing less. It is very very difficult. He is going against his very nature, but that is what he is called to to or not to do in this case.
This is the same for the homosexual. If he or she has those thoughts, he or she is called to resist them just like everyone else has to resist thoughts and behaviors that they may or may not be born with. Its hard. Being a Christian was never complex. Its just difficult. Pray and read your scriptures. There is refuge in the Word.