Here are some (preliminary) thoughts on a few things pertaining to homosexuals such as the sin of engaging in homosexual sex:
1. To start with, this should probably be obvious but homosexuals are sinners, not just homosexuals. They're no different from other people with respect to being sinners and sinful. Quite apart from whether or not they've engaged in homosexual acts, they've sinned in other ways such as by lying, hating, stealing, coveting, etc. Homosexuals are by nature sinners like heterosexuals and all people.
2. At least from what I understand, few homosexuals -- particularly male homosexuals -- are monogamous. In fact, many are quite promiscuous. This is itself sinful. That is, let's put aside whether homosexuals are having sex with other homosexuals. And let's simply ask whether they're having sex outside of marriage. If they are, then they're sinning.
However, for some this might raise the related question of whether homosexuals who are in a committed, monogamous relationship would be sinning if they were legally allowed to marry and were married. My immediate response is that I'm not talking about what's legal but rather what's moral. Sin is still sin even if it's legal. In other words, this would be sinful on the grounds that engaging in homosexual acts are in and of themselves sinful, or that homosexual "marriage" perverts the God-established creation ordinance of marriage between a man and a woman.
3. Some people argue that homosexuality is genetic.
- First off, even if homosexuality is genetic, does this then make it acceptable to engage in homosexual acts? No. Anger or perhaps the predisposition toward anger might be genetic, for example, but it doesn't make it right to murder someone.
- Some people have argued that there is a significant difference in the size of a particular region of a homosexual's brain relative to a heterosexual's brain. Even if this is true, how do we know that this is the cause of homosexuality rather than its result?
- Even if homosexuality is genetic, why should homosexuality be considered permissible on these grounds? Or even considered "normal"? There are many diseases such as certain forms of cancer which are genetic. But these diseases are not therefore "normal." In fact, that's why they are "diseases," because they are not normal; they are not markers of health.
- Even if homosexuality is genetic, it's not as if everyone with a gay gene is necessarily controlled by it. Even if there is a gay gene, it doesn't then follow that one is therefore compelled into homosexuality.
- At best, the existence of a gay gene might mitigate sin in some sense, but it would never excuse let alone condone sin.
- Now, if homosexuality is genetic, and if this in some way excuses homosexuality, then wouldn't the "inheritance" of our sinful nature from Adam excuse all sin -- which would be patently false?
- We've been talking about genetic factors (nature), but let's not forget about environmental factors (nurture). If we were raised in a home with physically and emotionally abusive parents, would this excuse our being physically and emotionally abusive towards our own children? No.
- Male-on-male and female-on-female sex is blatantly against how we were physically created. It overturns our sexuality. As John MacArthur once asked, with a touch of humor, "Do I need to draw you a picture of how a man and a man or a woman and a woman cannot possibly physically 'fit' together?"
- Homosexuality cuts against God's purpose for humanity as "male and female," as part of a family, as part of society. Men and women were created with distinctive roles. This is not a sexist statement; this is how God created us. This recognizes who we are as males and females, as husbands and wives, etc. And the family is the most fundamental building block of society. Note, for instance, that Eve was given her name because she was "the mother of all living" (Gen. 3:20). Her name is tied to her role as mother. Homosexuality does away with our God-given roles as men and women and as families.
There's also the related danger of homosexual couples adopting children. Imagine the possible affect on little Johnny or Jane growing up with two dads but no mom or two moms but no dad, to say nothing of the affect on others. I'm not saying it's a foregone conclusion but from what I've read and seen there does seem to be a high degree of deleterious effects in exposing and raising children within the context of a homosexual lifestyle.
- According to the Bible, there's a sense in which homosexuality demonstrates the height of sinful, rebellious man (à la Romans 1).
- We ought to reach out and love homosexuals (as we do others) by telling them the truth about their sins and their need for the Lord Jesus Christ as their Savior, just as Christ reached out to us and loved us. Homosexuals are no better or worse than other sinners in regard to the need for redemption. And we were once sinners like them, without hope and without God in this world.
- Also, some of us might want to keep in mind how emotionally and psychologically difficult it must be for the struggling homosexual (to say nothing of other difficulties). Is the homosexual destined to lead a life of unrequited love? Is he or she called to lifelong celibacy? And so on.
- Of course, there's much more to say. So I'd highly recommend reading stuff by someone like Robert Gagnon. There are some very good websites and weblogs under our "Culture Wars" category on the right sidebar too.