This debate has been raging for decades, if not longer. The interesting thing is that you can usually guess which side people are going to be on: it doesn’t depend so much on the scientific evidence (which is conflicting) but on their underlying beliefs and vested interests. The gay lobbyists will usually insist that homosexuality is something that people are invariably born with, and it’s easy to understand why: if something is genetic, that usually implies that you have no choice in the matter, that nothing can be done about it and that it should therefore be accepted as ‘normal for you’. But if it’s not determined before birth, then the situation can be interpreted very differently. It implies either that it’s your personal choice or that it’s the result of something that happened to you during childhood. And two consequences follow. Firstly, you can look around for someone to blame – either the gay person themselves (for making the ‘wrong’ choice) or maybe their parents (for not doing their job properly). Secondly, if sexual orientation is not genetically fixed, then what can be changed in one direction can (potentially at least) be changed back. So this is the viewpoint usually taken by those people who believe that homosexuality is either a disease or a sin.
But the fact is, we don’t actually know what causes someone to be homosexual. Despite a lot of research, nobody has yet discovered a ‘gay gene’; it isn’t as simple as that, and there are probably many different factors involved. Nor are all gay people the same; for a significant proportion, childhood experiences (such as sexual abuse) may well have played a part in determining their sexual orientation, but we shouldn’t assume that it must therefore be the same for all. The most important thing for the rest of us to realise is that for the vast majority, homosexuality is not a choice. Whether it’s inborn, or the result of something happening in childhood, or a combination of both, makes no difference: they are what they are, they have always felt that way, and they can’t (of themselves) do anything to change it.
Now Christians would say that all such things, whether caused by nature or nurture, are in some way a consequence of the Fall – the human race’s initial rebellion against God. God’s original intention, which we find in the early chapters of Genesis, was for human beings to form permanent, exclusive, heterosexual partnerships – what we now call marriage. This passage was the basis for Jesus’ tough teaching on marriage and divorce (Matthew 19:3-12). Any other kind of sexual relationship – casual, extramarital, or homosexual – is outside of God’s blueprint. But because the human race alienated itself from God, we now all find it difficult to live according to His blueprint, and some of us find it very difficult indeed. In our current culture, lifelong monogamy is out of fashion, while natural self-expression in sexual matters is not only very much encouraged but even claimed to be an essential need! There is thus a major culture clash between Christian teaching and the rest of society.
So what is the Church meant to do? Should we re-assess our ethics in the light of the modern understanding of human sexuality, and adopt the values of the world around us? Actually, this is not a new question, and the Bible is quite clear on the subject: Christians are meant to be different from the rest of the world, and sexual behaviour is one area in which the differences should be (and have always been) very obvious. So the most important thing for us to remember is that it’s not how we came to have our sexual orientation that matters, but what we do with it – and that applies to heterosexuals as much as to homosexuals. Adultery gets many more mentions in Scripture than homosexual sex.