As anyone who has read any recent literature on the topic will be able to tell, there is no word for homosexuality in Greek or Hebrew so while the Bible condemns many things, what we call homosexuality isn't one of them. First we have to define homosexuality. But that's a digression. Let me leave that aside and turn to the texts.
What does Romans 1 and I Cor 6:9 condemn? In the former case, idolatry. One of the behavioral consequences of idolatry is people who engage in same-sex relations by substituting the truth of God for a lie and who do things that are para physin (beyond nature). Romans 8 makes it clear that even while the pagan world of Romans 1-2 and the Jewish world of 3 falls under the judgment of God, nothing separates either from the love of God. I Cor 6:9 lists behaviors that will not enter the kingdom, including the Greek terms malakos and arsenokoites. When the term homosexuality was invented in the 19th Century, it appeared in some modern translations and replaced earlier translations relating the terms correctly to men e.g. tyndale for arsenokoites "abusers of themselyves with the mankynde." Sometimes an attempt was made in modern translations to separate the act from the person, so for arsenokoites read "practicing homosexuals." (This was at one time proposed for the NRSV).
A way to get at the meaning of arsenokoites is to look at other contexts in which the Greek word appeared independently of Paul. These other occurrences (Sibylline Oracles 2.70-77, Acts of John; Theophilus of Antioch Ad Autolycum) suggest that the word refers to some kind of economic exploitation by means of sex (but not necessarily homosexual sex). Perhaps the more important question is why some scholars are certain the word refers to male-male sex in the face of evidence to the contrary. Perhaps ideology has been more important than philology!
Malakos occurs widely in ancient sources and refers to the softness of expensive clothes, the richness of food, the gentleness of winds and breezes. The term refers to the effeminacy or softness of which penetration by another man is a sign or proof; it does not refer to the sexual act itself. In philosophical texts, the plural term malakoi are those who cannot put up with hard work. Xenophon uses the term for lazy men. In Josephus and Plutarch (both first century writers from different cultural backgrounds), cowards are malakoi.
In the ancient world effeminacy was implicated in heterosexual acts just as much as homosexual. Chariton in his novel Chaeras and Callirhoe provides a typical portrait of an effeminate man: he has a fresh hairdo, is scented with perfume, he wears eye makeup, a soft (malakos) mantle, and light swishy slippers; his fingers glisten with rings. He is off to seduce a woman! Why, given all the ancient evidence, some of which I have mentioned here, was the translation "effeminate" for I Cor 6:9 rejected by Bible translations? Because it reinscribes the misogyny of the term? Because condemnation of something socially embarrassing could hardly be called the word of God?
In short: the allegation that the New Testament condemns homosexuality is not just poor but lazy and inexcusable scholarship. An attempt by some scholars to interpret I Cor 6:9 by taking malakos to mean the passive partner and arsenokoites the active partner is based on circular reasoning. The meaning of arsenokoites is problematic. There is no evidence thatmalakos was ever considered as a technical term for a passive partner. (There are other terms for passive and active partner in Greek. They never appear in the NT) Malakos' general meaning of effeminate is independent of sexual position or object. To define malakos arsenokoites is to define something already clear by something that is obscure.
May I suggest some books? Brooten: Love Between Women; Nissinen, Homeroticism in the Biblical World. Also Dale Martin has an article on the two terms "Arsenokoites and Malakos: Meanings and Consequences" which I could send to anyone who asks in Biblical Ethics and Homosexuality ed. Brawley from which I took some of the above.
General Theological Seminary