The Supreme Court is hearing two cases on same-sex marriage bans: one challenging the Defense of Marriage Act (DOMA) and another challenging California's Proposition 8. As we gear up for another round of public debates, we expect some of the loudest voices to come from religious -- especially Christian -- communities. And although the number of Christian proponents of same-sex marriage is growing, we expect many Christians will stand opposed to same-sex marriage. To justify their position, some Christians will claim that history is on their side (for this reason, these folks have called theirs the "traditionalist" position).
A cursory overview of the history of early Christian conversations about sexuality, however, puts their claim on shaky ground. We find that same-gender sexuality was not a central point of contention for early Christians, who spent more time criticizing heterosexual marriage.
The earliest Christian communities considered heterosexual marriage to be fraught with problems and was thus to be avoided. Christian leaders argued that married people were too distracted by their familial obligations to be wholly devoted to God. Rather, they argued that the ideal sexual state for Christians was celibacy. They asserted that since the angels in heaven were asexual, Christians ought to remain single in order to live on earth already "as angels." They believed that Jesus would commend single and celibate Christians for "making themselves eunuchs for the sake of the kingdom of heaven" (Matthew 19:10-12). Finally, given that God's nature was virginal (literally "uncorrupted"), they claimed that Christian virgins shared God's very nature and were thus best able to commune with God.
Although the most dedicated Christians remained unmarried, heterosexual marriage and intercourse was tolerated in some cases. For those who could not control their lust, marriage absorbed their sexual impulses, keeping them from committing worse sexual sins. (Note here that marriage is defended not as a "good," but as better than other evils.) One of the only reasons to regard marriage as inherently good was that it produced children and that Christians who participated in procreative intercourse participated in God's creation.
Yet even those who found some value in marriage argued that married couples ought to refrain from sex as much as possible and especially when they wished to devote themselves to prayer, setting up sex and piety as mutually exclusive. Moreover, they stood resolutely against married couples who had sex only for pleasure and against all non-procreative sexual acts between married couples -- anal sex, oral sex, sex while pregnant, post-menopausal sex, etc. -- all of which were considered "against nature."
It was not Christians, but the pagan state that labored hardest to defend marriage. The poor conditions of life in the ancient Mediterranean made for regular population crises (each woman needed to have approximately five children to maintain a stable population). Thus, the state regularly incentivized marriage and procreation. Emperor Octavian (aka Caesar Augustus), for instance, introduced three waves of legislation that rewarded married people with children (e.g., with tax incentives, expanded rights and released obligations) and penalized the unmarried (e.g., taking away rights of inheritance or rights to hold office). Similarly, small tribes within the Roman Empire also prized procreation for the perpetuity of their line. This explains why tribes like the Jews endorsed sexual arrangements that maximized procreation (such as polygamy and Levirate marriage), lamented barren women and denounced all non-procreative behavior (including same-sex coupling).
Given this history, those who wish to appeal to tradition to comment on same-sex marriage must recognize two things: First, Christians who cull the tradition of Christian sexual ethics cannot seize only those aspects of the tradition that support their opposition of same-sex coupling while leaving behind other aspects of the tradition that criticize their own heterosexuality. If one wants to uphold the strand of pro-procreative logic in the early Christian tradition, she must recognize that the tradition requires her also to oppose all other forms of non-procreative sex acts that are performed only for pleasure, including those of married heterosexual couples, and to endorse sexual arrangements that maximize procreation (such as polygamy and marriage at a young age). Moreover, she must also acknowledge that early Christians considered heterosexual marriage and intercourse to be far inferior to Christian celibacy and in need of its own defense.
Second, the pro-heterosexual marriage stance of the Roman state was driven by issues of demographics, not morality. And while we'll soon see what the court understands to be the state's interest in the allocation of marriage rights, it's surely the case that our state faces none of the same pressures regarding under-population as did Roman backers of heterosexual marriage in antiquity.