There are three passages in the writings of Paul which have been supposed to deal with homosexual relations. Two words in 1 Corinthians 6:9 and one in 1 Timothy 1:10 have been taken at least since the early twentieth century to indicate that "homosexuals" will be excluded from the kingdom of heaven.
The first of the two, "malakos" (basically 'soft'), is an extremely common Greek word; it occurs elsewhere in the New Testament (e.g. Matt 11:8) with the meaning "sick" and in patristic writings with senses as varied as "liquid", "cowardly", "refined", "weak willed", "delicate", "gentle", and "debauched". In a specifically moral context it very frequently means "licentious", "loose", or "wanting in self-control". At a broad level, it might be translated as either "unrestrained" or "wanton", but to assume that either or these concepts necessarily applies to gay people is wholly gratuitous.
The word is never used in Greek to designate gay people as a group or even in reference to homosexual acts generically, and it often occurs in writings contemporary with the Pauline epistles in reference to heterosexual persons or activity.
What is more to the point, the unanimous tradition of the church through the Reformation, and of Catholicism until well into the twentieth century, has been that this word applied to masturbation. This was the interpretation not only of native Greek speakers in the early middle ages but of the very theologians who most contributed to the stigmatization of homosexuality.
No new textual data effected the twentieth century change in translation of this word: only a shift in popular morality. Since few people any longer regard masturbation as the sort of activity which would preclude entrance to heaven, the condemnation has simply been transferred to a group still so widely despised that their exclusion does not trouble translators or theologians.
The second word, "arsenokoitai", is quite rare, and its application to homosexuality in particular is more understandable. The best evidence, however, suggests very strongly that it did not connote homosexuality to Paul or his contemporaries but meant "male prostitute" until well into the fourth century, after which it became confused with a variety of words for disapproved sexual activity and was often equated with homosexuality.
The remaining passage, Romans 1:26-27, does not suffer from mistranslation, although little attention has been paid to the ramifications of its wording:
«For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature: And likewise, also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompense of their error which was met» (KJV)
There was a time, Paul implies, when monotheism was offered to or known by the Romans, but they rejected it (vv 19-23). The reference to homosexuality is simply a mundane analogy to this theological sin; it is patently not the crux of this argument. Once the point has been made, the subject of homosexuality is quickly dropped and the major argument resumed (vv 28ff.).
What is even more important, the persons Paul condemns are manifestly not homosexual: what he derogates are homosexual acts committed by apparently heterosexual persons. The whole point of Romans 1, in fact, is to stigmatize persons who have rejected their calling, gotten off the true path they were once on. It would completely undermine the thrust of the argument if the persons in question were not "naturally" inclined to the opposite sex in the same way they were "naturally" inclined to monotheism. What caused the Romans to sin was not that they lacked what Paul considered proper inclinations but that they had them: they held the truth, but "in unrighteousness" (v. 18), because «they did not see fit to retain Him in their knowledge» (v. 28).
[...]It is not clear that Paul distinguished in his thoughts or writings between gay persons (in the sense of permanent sexual preference) and heterosexuals who simply engaged in periodic homosexual behavior. It is in fact unlikely that many Jews of his day recognized such a distinction, but it is quite apparent that -whether or not he was aware of their existence- Paul did not discuss gay persons but only homosexual acts committed by heterosexual persons.