A recent Gallup poll finds that support for same-sex marriage has reached an all-time high. Currently, 70% of Americans say marriages between same-sex couples should be recognized by the law as valid, with the same rights as traditional marriages. The shift is primarily due to support by the younger generations: 84% of young adults, 72% of middle-aged adults, and 60% of older adults say they favor same-sex marriage. 

A majority of Republicans (55%) and more than two-thirds of Democrats (83%) support the legal change. Surprisingly, despite same-sex marriage being one of the most radically progressive political changes in human history, almost half of self-identified conservatives (48%) now endorse this redefinition of marriage.

The poll doesn’t list the breakdown by religion, but it’s clear that many Christians now believe they too should support same-sex marriage. Here are four reasons why we should uphold a traditional understanding of marriage. 

1. Marriage matters to God

“Have you not read that He Who made them in the first place made them man and woman?” said Jesus, “It says, ‘For this reason a man will leave his father and his mother and will live with his wife. The two will become one.’ So they are no longer two but one. Let no man divide what God has put together” (Matt. 19:4-6). 

Marriage was invented by God, not by man. We have neither the authority nor the ability to change what marriage is. The most that an individual or a government can do is misapply the term to relationships that are not actually marriages. Marriage requires the specific form of a union of man and woman (Gen. 2:24). Applying the term to same-sex unions, therefore, alters the very concept of what a marriage is for and what functions it takes.

Many people, including many Christians, think that objecting to same-sex marriage is imposing our moral beliefs on non-believers. In fact, the opposite is the case. It was advocates of same-sex marriage who imposed their view of sexuality on others by using the power of the state to enforce a criteria for marriage that is not rooted in the nature of marriage. In this way, they are similar to those who supported laws against interracial marriage. “Anti-miscegenation laws. . . were attempts to eradicate the legal status of real marriages by injecting a condition—sameness of race—that had no precedent in common law,” says philosopher Francis Beckwith. “For in the common law, a necessary condition for a legitimate marriage was male-female complementarity, a condition on which race has no bearing.” 

Christians should oppose any attempt to add conditions to marriage that change God’s standards.

2. Reality matters to God

When we say that a man can be married to a man or that a woman can be married to a woman, we are twisting the word “married” to mean what it cannot mean. If we use words in this way, we are making a claim about reality that we know is not true — and cannot be made true. In other words, we are endorsing a lie.

The Bible makes it clear that God detest lying or speaking untruths (Prov. 12:12). As Leviticus 19:11 says, “‘Do not lie. Do not deceive one another.” For us to use language that we know is deceitful and untrue about an institution created by God is harmful to our neighbors. Words matter to God, so they must matter to us.

3. Scripture matters to God 

As Paul told Timothy, “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work” (2 Tim. 3:16–17). From this and other passages, we derive the biblical doctrine of the sufficiency of Scripture, that Scripture is sufficient in that it is the only inspired, inerrant, and therefore final authority for Christians for faith and godliness, with all other authorities being subservient to Scripture.

The Baptist theologian Matthew Barrett says that sufficiency has real and serious implications for the church today. “First, although Christians claim they believe in the sufficiency of Scripture, they often live like they don’t, prizing their experience instead of Scripture’s instruction,” adds Barrett. “In faith and practice, too many Christians nod at what the Bible says, but politely set it aside to live their life how they think or feel is best.” 

Unfortunately, this is all too common when it comes to political and policy views. For many Christians in America, their secular political views — especially a left-libertarian view of sexuality and individual “rights” — informs their policy positions more than does the Bible. But Scripture matters to God and so it should matter to us.

4. People matter to God

As Christians, we are called to love our gay and lesbian neighbors (John 14:34), which is why we must not and cannot support same-sex marriage. 

Christians believe that marriage is a lifelong institution designed by God for our good and the good of our society. We also believe that homosexual sexual activity is sinful. How then could we support two people entering into a lifelong commitment that encourages them to engage in sin (1 Cor. 6:9)?

For a Chrisitan to endorse same-sex marriage is the opposite of loving — it is truly hateful. You do not love your neighbor by encouraging them to engage in actions that invoke God’s wrath and oppose God’s good design for humanity (Psa. 5:4–5; Rom. 1:18). You cannot love your neighbor and encourage them to engage in activity that will lead them to hell.

While we may be required to accept the presence of ungodly behavior in our society, the moment we begin to endorse it we too become suppressors of the truth. We cannot love our neighbor and want to see them excluded from the kingdom of Christ (1 Cor. 6:9).