There are quite a few reasons, actually. Here’s the best I can do to summarize:
…because I believe in marriage.
I’m not naïve. I know that marriage is no panacea. I am a child of divorced parents. I know first-hand that good marriages of good people can fail. And I know there are bad marriages—marriages that should end but continue—in abuse, in hatred, in a failure to love. Marriage is no panacea… but it is a prop. Marriage provides support necessary to help love do what love promises. C.S. Lewis wisely quipped that the god of passionate love, Eros, “is driven to promise what Eros of himself cannot perform” (The Four Loves). Eros needs Agape—the self-giving faithful love that does not depend on the response of the other or the emotions of the giver. Marital promises made in the light provide handrails when we grope in the darkness.
…because I believe in the separation of Church and State.
The USA is a pluralist country—filled with secularists, atheists, agnostics, and religious persons of many stripes. I think the US would do well to follow the example of some European counties—let the government recognize civil unions (for all people) and leave marriage to be defined by the religious traditions so long as these do not violate basic human rights (upholding real consent and the equal rights of all persons before the law). However, this is not how the current conversation is developing. Since state and federal governments are already in the marriage business, I believe it is discriminatory for the Federal Government not to recognize the unions of gays married legally under state laws.
I live in a state that provides marriage equality. I do not believe that sharing the rights I enjoy with others deprives me of those same rights. As a heterosexual married Christian woman, my marriage is not under threat. I believe that if I do not show generosity to others, I cannot expect it in return. In other words, if Christians insist on their views being legislated by the government, years from now, if Christians become a minority, they should not expect their religious views to be protected.
…because I believe in adoption.
I believe it is always best for children to be raised by their loving biological mother and father. This is the ideal. Unfortunately, this ideal often breaks down. Marriages fail. Parents abandon children. Some parents find themselves unable to provide for their children and—in valiant acts of sacrificial love or desperate end-of-rope decisions—look to others for help. Adoption is a heroic and necessary response to the breakdown of the biological family.
…because I believe some gays can be good parents.
Should gays be allowed to adopt? No, not all of them.
Should unmarried persons be allowed to adopt? No, not all of them.
Should heterosexuals be allowed to adopt? No, not all of them.
This is why adoption agencies have extensive (sometimes painfully-long) screening processes to determine to the best of their ability the fitness of individuals and couples for adoption. If some gays, some single persons, and some heterosexuals can show themselves ready and able to attempt the daunting task of parenting, by all means, let them adopt.
…because I believe it is possible that the conservative interpretations of the Bible on the issue of gay sexuality may be mistaken.
As a theologian and biblical scholar I am painfully aware of the difficulty of interpreting the Bible. Having studied anti-gay, pro-gay, and queer biblical scholars on this topic, I have found valid points (and weak arguments) on all sides.
While is it not obvious, it is nevertheless possible that the commands prohibiting same-sex sexual practice were written against contexts of abuse, pederasty, and/or cultic sexual practices (Lev. 18:22; 1 Corinthians 6:9-11; I Tim. 1: 8–11). No one can prove definitively either way—that they certainly were written against specific types of practices or that they were certainly not written against such practices. Interpretation always requires judgment and human interpreters are finite and fallible.
I do not believe Sodom has anything to do with the conversation. Gang rape is not gay marriage.
The general judgment against gay and lesbian sexual practice in Romans 1 does not fit the experience of many gay and lesbian Christians who have not rejected God, not been abused, not lived sexually promiscuous lives. Many have sought change and not found it. A good number do not find themselves gifted with the call to celibacy.
Celibate singleness should be a real option for anyone (regardless of orientation) and Christian communities must do better to support singles in our midst—lay persons as well as monks, nuns, priests, etc. At the same time, I also believe that marriage provides the healthiest context for sexual expression (I Cor. 7:9)—for the personal gift of the whole self, which sex can symbolize—this side of the resurrection (i.e., until marriage is no more, cf. Mt. 22:30).
…because after years of studying intersex I recognize that defining who is a biological man and who is a biological woman is more complicated than I once thought. In other words, enforcing the Defense of Marriage Act (DOMA) may be difficult in the years ahead.
…because I believe intersex persons also deserve the right to marry.
…because I believe that Adam and Eve represent the fruitful foundation not the final form of humankind.
The narrative of Adam and Eve is the beginning of the Christian story, not the end. Ours is a story that concludes with a crowd of diverse witnesses—men, women, eunuchs, intersex—people from every tribe, nation, and language, unified by worship not by uniform humanity. Adam and Eve may have been the first but are not the form into which all others must fit.
…because I know that “traditional” and “biblical marriage” are messy categories.
Marriages in the Bible, even the marriages of some of the heroes and heroines of our faith, while heterosexual, were far from the Christian ideal held by many today—the union of equal partners, both recognized as fully human; both joining by their own consent (not the will of parents); both joining for love, rather than economic interest, political strategy, or legitimate parenthood; both submitting to one another out of reverence and respect for the other, out of reverence for Christ.
I believe the union of one man and one woman is the marital patternpresented in the opening chapters of the Bible (Gen. 1-2) and that it is reaffirmed by Jesus (Mt. 19:1-2). At the same time, I also believe that loving, mutually-submissive, faithful, monogamous gay unions come closer to the current Christian understanding of marriage than many of the polygamous marriages of our Biblical heroes—Abraham, Isaac, Jacob, David, Solomon, and numerous others. If these ancient “exceptions” can be taken up into the story of God’s redemptive work, who are we to insist that God cannot also include others?
…because sometimes even God works “against nature.”
Looking closely at the book of Romans, Eugene Rogers notes that the very phrase used to denounce homoeroticism as “unnatural” in Romans 1:26 (para phusin) is found again in Romans 11:24 where it is God who is grafting Gentiles (non-Jews) into the (Jewish) covenant “contrary to nature.”
Rogers argues that God retains the freedom to graft gays into the vine of Christian marriage so that marriage can do its sanctifying work in the lives of these believers. He argues, “Marriage is a sacrament because it gives desire time and space to stretch forward … into things that are more desirable. Marriage allows sex to mean more.…‘Who devalues the body? Those for whom its gestures make no commitments, or those for whom they can make irrevocable commitments? Those who find freedom in casual nakedness, or those who reserve this most visible word for those whom they have something extraordinary to say? Marriage is a place where our waywardness begins to be healed and our fear of commitment overcome’—that, and much more.” [Rogers, “Sanctification, Homosexuality, and God’s Triune Life,” in Theology and Sexuality:Classic and Contemporary Readings, (London: Blackwell, 2002), 223-225.]
…because I know that in my own finitude and fallibility I could be wrong on this, but I believe there are good reasons to think as I do, and that there is grace for me if I am in the wrong, just as there is grace for you.
(Obviously this is not an ethical treatise or deductive argument. Rather, these are a set of convictions that have contributed to the evolution of my thinking. Please craft your responses in the comments accordingly and continue the tone of civil, generous dialogue—otherwise they won’t be posted. Thanks.)