Romans 1:21-32 (NIV)
For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles.
Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator—who is forever praised. Amen.
Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
Furthermore, since they did not think it worthwhile to retain the knowledge of God, he gave them over to a depraved mind, to do what ought not to be done. They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents; they are senseless, faithless, heartless, ruthless. Although they know God’s righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.
It’s essential to ask what the reason is for Paul’s condemnation of this clearly homosexual behavior. The reference is an analogy to the way in which Romans, having had the opportunity to follow the one true God, persist in polytheism. Paul uses the example of heterosexuals, who have the capacity to be engaged in authentic heterosexual conduct, who yet decide to spurt the “natural use” of their bodies in order to “burn in their lust” for members of the same gender. This is the end of the reference; once the analogy has been drawn, the main point can be engaged. But it’s still clear that Paul regards the perversion of heterosexuality to be a crime against the nature of the people involved.
But we should note that this is not a crime against “nature” as such; it’s a crime against the nature of individual heterosexuals. What Paul is describing here is heterosexuals engaging, against their own nature, in homosexual behavior. Just as the Romans after the revelation of Christ, these people can clearly do otherwise; they are resisting their own destiny.
Could this condemnation apply to people who are by their own nature homosexual? Unfortunately, Paul never explicitly addresses this point, since he seems to assume that every individual’s nature is heterosexual. But if we accept that some people are involuntarily homosexual, then the entire point become much more complicated. Indeed, to follow the logic completely, it is reversed. For by Paul’s argument, the key issue is that individuals act according to their own nature as it is revealed to them (as Christ was revealed to the Romans). By this logic, the person who is by his own nature homosexual would be acting against his nature by engaging in heterosexual acts. His destiny is homosexuality, just as the destiny of the Romans after Christ was monotheism.
Those who invoke Paul, then, have to make a further point to add to his. They have to assert that all people are by their own nature drawn to people of the opposite sex, and make a conscious and willful choice to rebel against it. Without invoking a general natural law, which was unknown to Paul, they have to say that each of us has his own heterosexual calling, and that our abandonment of it is deliberate and perverse.
This, of course, is the crux of the debate for prohibitionists have with others. They are confronted with a mass of data suggesting that the vast majority of people engaging in homosexual acts regard these acts as an extension of their deepest emotional and sexual desires, desires which they do not believe they have chosen and which they cannot believe are always and everywhere wrong. The psychiatric profession has concurred in this analysis. Historians record that in virtually all societies, there are records not only of homosexual acts but of distinct homosexual identities and communities and subcultures. Even the prohibitionists themselves have found it impossible to avoid the term “homosexual,” conceding by their very language that some people, by their own nature, appear predominantly or exclusively attracted to members of their own sex. If this is true, then Paul’s broad argument that people should not subvert their own nature actually becomes an argument against the prohibitionists and not in favor of them.
— Andrew Sullivan, Virtually Normal