Last summer in Australia, I discovered that my 5-year-old is better at throwing boomerangs than I am. In theory, boomerangs hit their “target” by returning back to the thrower. Mine, however, didn’t; it acted like a normal stick.
I share this story because one of the most seemingly persuasive arguments in favor of affirming same-sex marriage for believers suggests there’s a trajectory in Scripture from the Old Testament to the New that, if followed, finds its target in affirming same-sex marriage. Instead, I want to argue the trajectory of biblical sexual ethics is less like a stick whose target is away from its thrower and more like a boomerang that comes back to the one who threw it—only we discover the thrower is Jesus himself.
Trajectory Argument
Rather than trying to reinterpret the Bible’s prohibitions, many who affirm same-sex marriage acknowledge that the New Testament does prohibit same-sex sex. But, they argue, Christians can nonetheless embrace same-sex marriage because the trajectory from the Old Testament to the New is one that (if continued) ends in validating same-sex marriage.
Proponents of this view often point to the consensus among Christians that slavery is wrong, despite the multiple New Testament texts that seem to endorse slavery. If we can say the New Testament points us toward the abolition of slavery, even though it doesn’t quite get there, the argument goes, we can likewise argue it points us toward same-sex marriage, even though it doesn’t get there. This comparison packs a rhetorical punch because of the appalling history of race-based, chattel slavery in the United States, which many Christians on both sides of the Atlantic tried to justify from Scripture.
So is it true that the Bible’s movement is toward rejecting slavery and embracing same-sex marriage? Let’s begin at the beginning.
Beginning of Humanity
The Bible’s first chapter declares that human beings, male and female, are made in God’s image (Gen. 1:27). This is the first foundation for universal human equality and the first blow to the idea that some humans should be enslaved because they’re innately inferior. All humans are God’s image-bearers. The only differentiation in this text is between male and female, both of whom are called to rule over creation and to “be fruitful and multiply” (vv. 26–28).
The Bible’s first chapter declares that human beings, male and female, are made in God’s image. This is the first foundation for universal human equality.
In Genesis 2, we focus in on one man and one woman, brought together in a “one flesh” union, which is the prototype for future marriages: “Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh” (2:24). Marriage is defined as one man and one woman, permanently bonded.
We read that “the man and his wife were both naked and were not ashamed” (v. 25). But in Genesis 3, sin enters the world and undermines both the man and woman’s shame-free relationship with God and their shame-free relationship with one another. From then on, we see sin of all kinds—including sexual sin—portrayed in the Bible. We also see slavery, even at the beginning of the story of God’s people.
Beginning of God’s People
When God calls Abraham and promises to bless him and give him offspring similar in number to the stars, Abraham is married to one woman. But since Abraham and Sarah are old and infertile, Sarah suggests that Abraham take her Egyptian servant Hagar as a functional second wife (16:1–4).
This isn’t what God commanded. It shows a lack of trust in God. In the cultural terms of the day, however, it would’ve been a status upgrade for Hagar. This whole scenario is completely alien to us. We assume women should always choose their husbands and that polygamy is wrong. In ancient Near Eastern culture, by contrast, women almost never chose their husbands, and polygamy was normal for wealthy men.
We see Hagar’s sense that she’s received a status upgrade when she gets pregnant and starts to look down on Sarah. Sarah reacts so harshly that Hagar runs away. But the Lord finds Hagar in the wilderness, tells her he has listened to her affliction, and makes promises to her that echo his promises to Abraham (vv. 9–11). Remarkably, Hagar becomes the first person in the Bible to give God a name: “She called the name of the LORD who spoke to her, ‘You are a God of seeing,’ for she said, ‘Truly here I have seen him who looks after me’” (v. 13). So in the Bible’s first slave narrative, an Egyptian servant is personally seen and cared for by the Lord.
In an ironic reversal of Hagar’s story, the second slave narrative is that of Abraham and Sarah’s great-grandson, Joseph, who’s sold to slave traders by his brothers and then bought by an Egyptian commander, Potiphar (37:25–36).
Unlike in American history, slavery in the ancient world wasn’t associated with one racial group, and slaves could become quite high status, which we see when Potiphar puts Joseph in charge of all his affairs (Gen. 39). But when Joseph refuses to sleep with Potiphar’s wife, she claims he tried to rape her, and he gets thrown in prison. God nonetheless is with Joseph, and his story ends with him as Pharaoh’s right-hand man, rescuing his own family from starvation. Once again, God vindicates the enslaved.
Exodus begins with all the Israelites living as slaves to the Egyptians. But God listens to the Israelites’ affliction (Ex. 3:7), just as he listened to Hagar’s (Gen. 16:11), and he rescues them. From then on, the story of God’s people is a story of emancipated slaves.
Old Testament Law
When God gave his people laws, he kept reminding them they were once slaves and should therefore identify with the enslaved (e.g., Ex. 20:2; Deut. 5:6; 15:15). In the ancient world, people often sold themselves into slavery as an alternative to destitution. But God’s law made man-stealing and slave- trading a capital offense (Ex. 21:16). It also prescribed significant protections for all slaves, including a day of rest (e.g., 20:10; 21:1–32), and guaranteed freedom in the seventh year for Israelites who sold themselves into slavery (Deut. 15:12–15).
When it comes to the Old Testament laws regarding sex, we see explicit prohibitions on adultery (e.g., Ex. 20:14) and on men having sex with other males (Lev. 18:22). We also see restrictions on divorce and on using women sexually without marrying them (Deut. 21:10–14). But while polygamy is never commanded and often portrayed negatively, we don’t see polygamy prohibited.
So, what movement if any do we see between the Old and New Testaments when it comes to sex and slavery?
Slavery in the New Testament
As Kyle Harper and others have shown, during the time in which Jesus was born, at least 10 percent of people living in the Greco-Roman empire were slaves. Some sold themselves into slavery. Some made enough money to buy their freedom. Some were subjected to hard labor and physical abuse. Others were skilled professionals, like doctors or accountants, earning more money and living more comfortably than many free people. But it was generally assumed that slaves were there to serve their masters.
The story of God’s people is a story of emancipated slaves.
It was therefore shocking when Jesus declared to his disciples, “Whoever would be great among you must be your servant, and whoever would be first among you must be slave of all. For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many” (Mark 10:43–45). Jesus here upended the whole paradigm of slavery. Jesus claimed to be the rightful King of all the universe. But he deliberately embraced the role of slave and called his followers to serve one another.
In line with this great reversal, Jesus taught that he’s the master who serves (Luke 12:35–40) and stunned his disciples by dressing himself like a slave and washing their feet—a role typically taken on by slaves—before telling them to follow his example (John 13:1–20). Even in death, Jesus identified with slaves, since crucifixion was typically inflicted on slaves. So, in Jesus, we see the Lord of all creation taking on a slave’s role, dying a slave’s death, and telling us to follow his example.
The apostle Paul got the memo, calling himself a “slave of Christ Jesus” (Rom. 1:1; Phil. 1:1, HCSB). Paul is sometimes seen as supporting slavery because he instructed enslaved Christians to serve well (e.g., Eph. 6:5–8). But his basis for this teaching was not that slaves were inferior (as the paradigm of slavery assumed) but that they were really serving Jesus (Col. 3:22–25). Likewise, Paul commanded masters to treat their slaves “justly and fairly” because they have a “Master in heaven” (4:1; cf. Eph. 6:5–9). Indeed, Paul deliberately undermined the slave-free distinction by declaring Christian slaves were Jesus’s freedmen, while free Christians were Jesus’s slaves (1 Cor. 7:21–23).
Paul taught a radical equality rooted in the gospel: “Here there is not Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave, free,” Paul wrote to the Colossians, some of whom were slaves, “but Christ is all, and in all” (Col. 3:11). Likewise, he explained to the Corinthians that they were all members of one body regardless of their status in the world: “For in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free” (1 Cor. 12:13). The gospel message that the Son of God died so sinners could be forgiven and united with him and with each other demolishes slavery’s foundations.
We see a practical example of Paul’s ethics in his letter to Philemon. Under Roman law, Philemon could have severely punished Onesimus, a slave who had run away from him. Instead, Paul calls Onesimus his “son” and “very heart” (Philem. 10, 12, NIV) and tells Philemon to welcome Onesimus back, “no longer as a bondservant” but as “a beloved brother” (v. 16). Indeed, he tells Philemon to receive Onesimus as he’d receive Paul himself (v. 17). This overturns the master-slave relationship and turns it into a brother-brother bond. Movingly, while Paul refers to other gospel partners as his “fellow slaves” (e.g., Col. 1:7; 4:12, HCSB) he simply calls Onesimus “[our] faithful and beloved brother” (4:9).
To summarize, when it comes to slavery, you could say we see a progression in the Bible from protections and provisions in the Old Testament to the radical reversal of the master-slave relationship that Jesus both embodied and commanded. But while the gospel torpedoes slavery’s foundations, it also reinforces the first foundation for equality: that all humans are made in God’s image. Jesus is “the image of the invisible God” (1:15), and in him, our equality and unity is finally fulfilled.
No wonder Christianity was so popular with the enslaved that it was mocked in the second century as a religion of slaves, women, and children. No wonder the first known explicit argument against slavery was made in the fourth century by a Christian bishop on the basis of all humans being made in God’s image. No wonder slavery was progressively eradicated as Christianity spread through Europe in the 7th to 10th centuries. When the transatlantic slave trade started up, it represented a horrific and unjustifiable reversion to pre-Christian practices. And it was Christian arguments and activists who led abolition.
The famous seal of the Society for the Abolition of Slavery in England from the 1780s was a picture of an enslaved man kneeling in his chains and asking, “Am I not a man and a brother?” The Bible’s answer to both these questions is an emphatic yes. In 1837, this seal was printed in the United States along with the Old Testament law against man-stealing and a poem that exclaimed, “What! God’s own image bought and sold!” and warned of God’s coming judgment against those who enslaved their fellow image-bearers. In short, the history of race-based chattel slavery in America is utterly unjustifiable from Scripture.
Sex and Marriage in the New Testament
What about the biblical progression when it comes to sex and marriage? Do we see a trajectory from the Old to the New Testament that (if continued) opens space for same-sex marriage?
The history of race-based chattel slavery in America is utterly unjustifiable from Scripture.
Jesus’s radical welcoming of people known for sexual sin is sometimes seen as a relaxing of the Old Testament laws concerning sex. But Jesus actually tightened them.
Jesus took the commandment against adultery and extended it to include lustful thoughts (Matt. 5:27–28). Jesus condemned all forms of sexual immorality as sinful and observed that sexual sin comes straight out of our hearts (15:19; Mark 7:21). When asked about divorce, Jesus defined marriage as a lifelong, one-flesh union between one man and one woman—boomeranging back to God’s original design (Matt. 19:4–6). He underscored that marriage is male-female by quoting Genesis 1:27 and defined it as monogamous: “The two will become one flesh” (v. 5, NIV; Gen. 2:24).
When it comes to same-sex sexual relationships, the Old Testament prohibition on men sleeping with males is reasserted (e.g., 1 Cor. 6:9–11; 1 Tim. 1:9–11) and women sleeping with women is also portrayed as sinful (Rom. 1:26–28). What’s more (awkwardly for the trajectory argument), one of Paul’s prohibitions on male-male sex is right next to his explicit condemnation of enslaving. Using a word built on the Greek translation of the words for “male” and “bed” in the Old Testament prohibition on men sleeping with males, Paul calls both enslavers and men who sleep with males “lawless and disobedient” (1 Tim. 1:9).
But rather than excluding those (like me) who are drawn to same-sex sexual relationships, Paul notes that some of the first Christians came to Christ with a background of same-sex sexual sin and that they (like all who come to Jesus) were washed, sanctified, and justified in his name (1 Cor. 6:9–11).
The boundaries around sex in the New Testament are clear: any sex outside of male-female, lifelong marriage is sinful. But just as the gospel lies at the heart of the Bible’s demolition work on slavery, so it lies at the heart of its vision for male-female marriage.
Jesus the Bridegroom
In a curious move for someone who never married, Jesus called himself “the bridegroom” (Mark 2:19–20). To understand him, we need to look back to the Old Testament, where prophet after prophet pictured God as a faithful husband and Israel as his frequently unfaithful wife (e.g., Isa. 54:5; Jer. 3:20; Ezek. 16; Hos. 2). As God-made-flesh, Jesus declares he’s the Bridegroom, come to claim God’s people for himself.
Paul presses on this metaphor, presenting Christian marriage as a picture of Jesus’s love for his church (Eph. 5:22–33). Strikingly, Paul quotes from Genesis 2:24—“Therefore a man shall leave his father and mother and hold fast to his wife, and they shall become one flesh”—and then declares, “This mystery is profound, and I am saying that it refers to Christ and the church” (Eph. 5:32). According to Paul, God’s original design for marriage was modeled after the everlasting, one-flesh union between Jesus and his church.
Like a husband and wife, Jesus and his people aren’t two interchangeable parties. Their union is across deep difference. In marriage, it’s the difference of male and female that enables sex and the creation of new humans. Likewise, Jesus’s love for his church is intimate, life-giving, and fruitful.
This biblical metaphor helps us understand why marriage must be male-female. It also helps us understand why Christian marriage is monogamous. Jesus’s relationship with his church isn’t a love depicted by polygamy: one man with many spouses. It’s a love depicted by monogamy, because his people are “one body” (Rom. 12:5; see also 1 Cor. 10:17; 12:12, 20; Eph. 2:16; 4:4; Col. 3:15). But this same metaphor helps us to understand why deep love between believers isn’t limited to marriage.
One Body Together
Many people think that Christians who say no to same-sex sexual relationships have no vision for love between believers of the same sex. But nothing could be further from the truth. Jesus prayed that his followers would “be one” (John 17:11, 21–22) and commanded them to love each other like he loves us (13:34–35; 15:12).
The boundaries around sex in the New Testament are clear: any sex outside of male-female, lifelong marriage is sinful.
Rather than presenting marriage as by far the greatest love relationship, Jesus declares, “Greater love has no one than this, that someone lay down his life for his friends” (15:13). Following Jesus’s lead, in the rest of the New Testament we find a relentless call to brotherly and sisterly love because Jesus died for us and we’re members of his body (e.g., Rom. 12:10; 13:8; Gal. 5:13; 1 Thess. 3:12; 4:9; 1 Pet. 1:22; 1 John 3:11, 23; 4:7–12). “By this we know love,” John writes, “that he laid down his life for us, and we ought to lay down our lives for the brothers” (1 John 3:16).
Our union with brothers and with sisters in the Lord isn’t expressed in sexual or romantic ways outside male-female marriage. But if we’re followers of Jesus, it’s true love.
Boomerang Returns
In Revelation, we see the endpoint of all biblical trajectories. On the one hand, we see slave traders lamenting (Rev. 18:11–17), and we see sexual immorality outlawed one last time (22:15). On the other, we see a countless multitude from every racial and ethnic background worshiping Jesus together (7:9–11), and we see the wedding of the Lamb, as Jesus and his church are brought together for eternity (19:6–9; 21:1–4; 22:17).
In Jesus the Bridegroom, we unlock the meaning of male-female marriage. In Jesus the eternal King, who came “not to be served but to serve, and to give his life as a ransom for many” (Mark 10:45), we find the wrecking ball for slavery and the best foundation for human equality. Scripture’s trajectory isn’t toward abolishing slavery and affirming same-sex marriage. It’s a boomerang trajectory that brings us back to the beginning when humanity lived in an unhindered love relationship with God and with each other—but makes it so much better.
When God’s people are finally united with Jesus as a bride with her groom, there will be no human marriage anymore (Matt. 22:30). But we’ll all experience the ultimate fulfillment of all our hopes and dreams of love (Rev. 21:1–4). “Surely I am coming soon,” Jesus declares. “Amen. Come Lord Jesus!” (22:20).