Homosexuality and the Bible: Two Views is a debate between Dan Via and Robert Gagnon, both New Testament professors. Via takes the view that the church should affirm gay marriage, Gagnon affirms the traditional view of homosexual sex as sinful.
What was interesting and surprising to me was that Via affirmed that 'the Biblical texts that deal specifically with homosexual practice condemn it unconditionally' (p93). He believes that rules (Biblical injunctions in this case) can be overrided if you have enough good reasons (p21).
His view of Scripture is essentially that it is 'authoritative only in those parts that are existentially engaging and compelling' and should be re-interpreted in the light not only of new knowledge but 'in the light of one's own interpretation' (p2).
Via's main argument rested on the issue of orientation. He argues that Paul (Romans 1:24-27 and 1 Cor 6:9-10) and the Biblical witness against homosexuality applies only to those who are acting against their nature. So straight people acting gay. What it does not apply to are people who by nature are gay. For them it is natural to live gay, it's not against their nature but with their nature. He argues that if Paul knew then what we knew now he would say the same. That denying gay marriage both encourages promiscuity within the gay community by not supporting faithful, monogamous relationships and is unjust by denying some of God's creation the possibility of finding sexual fulfilment.
Gagnon by contrast deals comprehensively with every Biblical passage, examines context, makes good exegetical links and connections (and one or two weaker suggestions such as reference to Ham & Noah that is far from convincing). He agrees with Via that the Bible uniformly, unequivocally and consistently calls same-sex sex sin and sees no reason why the church should change its mind now.
He argues that instead, the Bible offers the 'beautiful image of 'one fleshness' of marriage as a reunion of an original binary whole' (p89). The joining of two constituent parts male and female, that together reflects the image of God in a way that one half on their own cannot. Anything contrary to that falls short of God's creative intent.
Via sees orientation as unchangeable and refers to gay experience to support that (I assume not really giving weight to the experience of those who are post-gay and have left that lifestyle behind), while Gagnon believes God's grace is more powerful than even the strongest of our desires.
Robert Gagnon has made available a wealth of articles available on his website.