Same-sex marriage was perhaps the most contentious issue of the past ten years in the United States. Many Christians stood opposed to recognizing same-sex marriage, claiming that marriage is between a man and a woman. I believe that this is true. I also believe, however, that the case for “traditional” marriage was undercut by the fact that our entire nation seems to have adopted the idea that marriage’s purpose is to bring personal fulfillment.

If that is the purpose of marriage, then why in the world would it be important that the fulfillment should come between a man and a woman instead of through two men or two women? After all, as the slogan goes, love is love.

Certainly love is love. After all, if you say a word and then say “is” and then say the same word again, then you have made a true (albeit obvious) statement. Love is love, but not all love involves sex and lifelong one-flesh commitment. The friendship between David and Jonathan (1 Samuel 20) or between Ruth and her mother-in-law Naomi (Ruth 1) are powerful examples of love. And the gospel of Jesus is reflected in this sacrificial love. But both of these examples are different from the one-flesh love of marriage.

If the purpose of marriage is self-fulfillment, then there’s hardly a case to be made against same-sex marriage. In fact, there’s hardly a case to be made against no-fault divorce in this model. If, however, marriage is about putting the gospel of Jesus on display (Ephesians 5:22-33), then this has implications into how marriage works.

Marriage, most simply, is about a one-flesh relationship. This is the first word on marriage in the Bible. Genesis 2:24 says, “That is why a man leaves his father and mother and is united to his wife, and they become one flesh.” The idea is that a man and a woman join their lives together not only physically, but emotionally, financially, practically, and in every other way. This is why I don’t advise separate bank accounts or pre-nuptial agreements. I believe that these undercut the one-flesh nature of marriage.

That said, the one-flesh nature of marriage is reflected specifically when a man and a woman are joined. The narrative of Genesis 2, when God creates Eve, reflects the idea that Eve is like Adam, but different from him. He is joined to someone who is his same species but brings something different to the table. This reflects what is so special and powerful about marriage. When a man and a woman join their lives to one another, a gap is bridged. A barrier is overcome.

This reflects the gospel in a way that is different than any male-male or female-female relationship. It is not that there can’t be powerful same-sex friendships or connections, but that these don’t fit into what God was doing when he created marriage. And he reserved sexual activity for marriage specifically because sex is the physical manifestation of the one-flesh relationship that marriage is.

Those of us who are believers are called to look at our marriages not simply as opportunities for us to experience love and acceptance (although this is certainly God’s desire for us within our marriages). Our marriages are about telling a story to the world.

The story is about a God who is so deeply committed to us that he is willing to sacrifice everything for us, even when we are unworthy. It is the story of a groom who promises that he will never leave us or forsake us. And when we embrace this story, it transforms how we approach God’s gift of marriage.