Recently, Hebrew Bible scholar Esther Hamori has written two insightful pieces engaging this problem directly. The first dealt with the highly controversial issue of marriage specifically, and the second highlights the diversity of voices within the Bible itself, an important reality often overlooked or minimized in conservative Christian circles. I highly recommend reading both of her articles with an open mind. Here's the closing thought from the second piece:
Religious diversity is an inherent part of the biblical tradition. The Bible has significant internal variation, and there are different thoughtful ways to deal with that, but ignoring it is not one of them. My own take on this is that the rich complexity of the spectrum of voices is the very thing that gives the Bible its remarkable texture and depth, and that if the Bible is used as a "model" for anything, perhaps it could be used as a model for honest engagement with such a variety of viewpoints. But that's just me, and I'd expect another voice to say something different.Her final words illustrate her expectation of push-back, disagreement, and discord inspired by her view. I know many people who would likely object strenuously to her perspective, but I find her call for "honest engagement" to be welcome and refreshing. I agree wholeheartedly.
Regarding her first article on marriage, I have to say (at the risk of offending or surprising more conservative readers including friends and family) that I agree with Hamori that the Bible reflects a variety of culturally-bound acceptable standards for marriage. In fact, evangelical Old Testament scholar John Walton uses the analogy of marriage in The Lost World of Genesis One to illustrate how we might use the same word to describe marriage today and marriage in the ancient Near East, but the word points to two very different cultural concepts. The cultural context is essential to properly defining what is actually meant by the term. Studying the biblical text in its ancient Near Eastern context and attempting to see the text through the worldview of the ancient world is an indispensable part of interpretation.
That said, I don't personally find this multiplicity of voices about marriage to necessarily serve as biblical support for gay marriage. Hamori doesn't explicitly offer it as such, but the implication is there. Her conclusion to the marriage article states:
Marriage in the Bible is not restricted to one man and one woman. The biblical models for marriage include a range of relationships and combinations, and these evolve with the culture.The point is that marriage norms change with the culture. I won't argue that, just point out this is a cultural, not a biblical, argument in favor of gay marriage.
I will point out, however, that conservative claims of support for the "biblical definition of marriage" as one-man and one-woman are simplistic and narrow in their interpretation. Yes, Genesis 2:24 supports the "one flesh" sexual union of a man and a woman but calling that "marriage" in the sense of 21st century United States legal status is overreaching. Yes, Paul offers support for marital monogamy (1 Cor 7:2; 1 Tim 3:2), but that was the norm in the Greco-Roman world and in first century Judaism. Paul's support simply mirrors marriage norms of his day. Marriage as a legal and socio-cultural institution is one of the most culturally-bound categories in the world. Rather than appeal to the "biblical definition of marriage," supporters of traditional marriage should simply acknowledge it as such--they support traditional marriage according to centuries-old mores of Western civilization.
One final thought for those engaged in a defense of traditional marriage as "biblical": what's the biblical or theological rationale for Christians to mobilize politically in an attempt to force Judeo-Christian morality on an unbelieving culture that doesn't want it? (J. R. Daniel Kirk had a good post a few months back on this issue if you're interested.)
The bottom line here is that we would all benefit from more open dialogue and less partisan bickering over whether the Bible supports our cause or not.