I have sometimes seen well-intentioned commentators say that the Church needs to insist that a Christian marriage is only between a man and a woman. Similarly, I have seen others make an argument that the Church should get out of the culture war over the definition of civil marriage, and just retreat to, and defend absolutely, the idea that a sacramental marriage must be between a man and a woman.
I think this would be a mistake.
I don’t mean, of course, that a Christian marriage, or a sacramental marriage, can be anything other than a union between a man and a woman. I mean instead that I think it would be mistaken for the Church to limit itself to defining only what a Christian or sacramental marriage is. It can’t do that and remain faithful its historic teaching.
That teaching has always held that marriage is by nature a union between a man and a woman. The Church has never suggested that there is a radical difference between the kind of persons (one male, one female) needed for a natural marriage versus a sacramental marriage. The Church has, I believe, acknowledged that not all marriages are sacramental. But even there its teaching has never suggested anything else than that a non-sacramental marriage would be a union between a man and a woman. The Church–like most of the rest of humanity for most of its history–has just never applied the word marriage to anything other than a male-female union.
Sticking to the traditional definition of marriage–whether or not we are talking about sacramental marriage–is not just a matter of stubbornly staying with ancient assumptions. It is also a matter of fidelity to the teachings of Jesus Christ, whom Catholics believe to be the founder of their Church and, indeed, to be God. For the New Testament records Jesus as teaching that marriage is by nature a union between a man and a woman. In the Gospel of Matthew (Chapter 19), when the Pharisees approached Jesus and asked him about the legitimacy of divorce, he responded that God had from the beginning made them male and female, and had said that a man leaves his father and mother and cleaves to his wife, becoming one flesh with her.
There is no immediate question here about sacramental or Christian marriage. Jesus was asked and is talking about the practice of marriage among the Israelites from long before this conversation took place. And his references to the plan of the creator make clear that he is here talking about the nature of marriage for human beings as such.
In short, the Church’s teaching that marriage is by nature a union between a man and a woman is Jesus’ teaching that marriage is a union between a man and a woman. For that reason, I don’t see how the Church could stop teaching that idea and remain faithful to its mission.
This is not to say that the Church has to commit itself absolutely to any particular strategy or political activism in America’s culture wars. Maybe the culture will become so different from what it used to be that it would become pointless for the present to engage in any political activity on behalf of restoring the true meaning of marriage as publicly authoritative. But the Church certainly has an obligation to keep teaching what marriage actually is, for anyone who will listen.