Now, there are two really good arguments that the "christian-gay" community have:
1) that sodom and gomorrah's homosexuality was not the same as that of today, which is more faithful to one partner vs. gang rape, and multiple people. The argument is that a faithful relationship with the same gender is not lust, but commitment.
And 2) that the "unnatural" argument Romans throws out is targeting heterosexuals who change to homosexuals; thus, not condemning the homosexual "born" that way.
Both sides are wrong to argue "natural" by way of science. That simply is not the way the ancients used the word. Concentrating on the phrases "according to nature" and "against nature" is a red herring.
As the Stoics formalized their philosophy, certain words and phrases took on specialized meanings. The phrases "according to nature" and "against nature" in their formal writings became moral judgments. "Against nature" was almost interchangeable with another of their formal phrases: "that which ought not be done."
Just as today the common people misuse psychological terms and empty them of most of their meaning, so too did the common people back then with philosophic terms. For the common people, the meaning shifted from "what ought [not] be done," to "what ought [not] be expected of them." There was a shift away from (but not a total split from) the idea of i being
morally right or wrong, to the idea of being how it is done -- not the "right" thing to do it but just the thing to do. (With an unconscious attitude of that's the way it has always been. For many people "according to nature" simply meant "what I expect," and "against nature" meant not what i expected."
In his other letters, Paul seems to use the phrases in that more common way. Short hair on men is "according to nature" and God's grafting of the wild olive branches onto the domestic tree is against nature. But in Romans 1, Paul seems to be aiming his meaning in the gray area between the formal Stoic definition, and the popular usage, so that the reader can assume that Paul is agreeing with his opinion of the issue, no matter what opinion he held.
You see, the two phrases were a red herring for the original readers as well. To lull the into believing that Paul agrees with their opinion on the terrible sinners all around them. The are the bait for the trap lying in wait in Romans 2:1-3
I'm pretty sure they'd say that 1 Cor. 6:9's word of "homosexuality" is the greek word: malakos, which means (according to a greek-english dictionary) limber, soft, smooth, mild...not necessarily "homosexual." Other translations say "effeminate," which really does mean "lady like," but the argument is over the translation of greek to english.
Although "
malakos" (soft) was used at least once to mean graceful, that was in an advertisement by a dancer commenting on his dancing skills. It was rarely, if ever, used to label someone effeminate.
Most often it was used to indicate someone whose muscles were less developed, less hard. It could be used either positively or negatively. And, when used as a negative, the idea often shifted from physical strength to strength of character. By not exercising virtue and resisting vice, a person was no longer able to resist the temptation of his special vice.
There is not enough information to know what temptation they can't resist. Possibly that is deliberate. If we don't know which particular sin haunts the "
malakos" sinners, we are all free to assume it might be the same as our own greatest temptation, whatever it may be, and so place ourselve in the "
malakos" sinners' place: standing in the need of God's grace.