What Does the Bible Teach About Sexuality?

More than fifteen hundred years have passed since the fall of the Roman Empire, yet the moral decay and indulgence that contributed to its collapse continue to echo through Western civilization today. The Roman statesman and orator Cicero once proclaimed, “History is the teacher of life” (Historia magistra vitae est). While proponents of so-called “progressive” lifestyles celebrate their cause, history reminds us that what is labeled as progressive is often regressive.

This regression, though troubling, is not entirely surprising. What is truly alarming, however, is the eagerness of the visible church to adopt secular ideas about sexuality, even celebrating them as virtuous. Ordaining “gay pastors” was once thought to be confined to mainline denominations—surely, a Reformed church would never host an LGBTQ-affirming conference. Or would it? In the midst of such widespread confusion, God’s light shines in the darkness.

To understand biblical sexuality, it’s essential to consider both the biblical proscriptions—God’s “no”—and the biblical prescriptions—God’s “yes.” A comprehensive understanding of what the Bible teaches about sexuality requires a well-rounded and thoughtful theology on the subject. At its core, a proper theology of sexuality must begin with the foundation of marriage. In fact, one of the most compelling defenses of biblical sexuality is presented by Jesus Himself in the gospel of Mark.

From the beginning of creation: 

“God made them male and female.” “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” So they are no longer two but one flesh. What therefore God has joined together, let not man separate. (Mark 10:6–9)

Jesus responds with a sharp rebuke, condemning the practice of ending marriages for trivial reasons and exposing the hardness of their hearts (Mark 10:5). Rather than drawing from the many passages that affirm the lifelong nature of the marriage covenant, He points to the foundational example—the union of Adam and Eve. This Edenic prototype underscores the sacred and covenantal essence of marriage as God intended.

Marriage is a sacred institution created by God, making Him the One who unites man and woman as one. The command “Let not man separate” reminds us that divorce contradicts God’s design and intentions “from the beginning.” It is not for humans to undo what God has joined together. To intentionally forsake the marriage bond without biblical grounds is, in essence, an act of defiance and an attempt to usurp God.

If Jesus’ sole intention was to reaffirm the unity of marriage, referencing “one flesh” from Genesis 2:24 would have sufficed. Yet, He deliberately includes the binary distinction of “male and female” from Genesis 1:27—a detail that may initially seem unrelated. However, it is deeply relevant: the institution of marriage is inseparable from the biblical framework of male and female.

Jesus tethers the creation of “male and female” (Gen. 1:27) to the creation of the “one flesh” marital union (Gen. 2:24). This beautifully illustrates that God both differentiates male and female at creation and unites one male and one female in marriage. Thus, when God made male and female, He already had in mind the marital union that followed.

Genesis 1:27 carries profound implications for marriage and humanity that cannot be overlooked. This verse not only establishes the reality of sexual differentiation but, more importantly, serves as the foundation for the doctrine of the imago Dei. Thus, Jesus’ words in Mark 10:6–8 teach us not only that male and female are essential to marriage but also that marriage points to the image of God—thus bringing together both the nature of marriage and the nature of humanity.

Marriage, therefore, is not a basic human or civil right but a sacred covenant designed by God. As Christians, we do not claim rights of our own; our only identity and purpose are found in Christ. Furthermore, sex is not about personal freedom or what individuals choose to do with their bodies.

“From the beginning,” God’s design for marriage is a lifelong covenant between male and female, intended to reflect His own nature and character. Any distortion of marriage—including adultery, premarital sex, or same-sex unions—not only violates God’s will but also dishonors the image of God that marriage is designed to reflect.

The confusion surrounding sexuality today is not just a cultural issue—it’s a spiritual one. When we distort marriage and sexuality, we are distorting the very image of God. But Christ, the perfect image of God (Col. 1:15), came to restore what was broken. He calls us not to conform to the world’s shifting definitions but to be transformed by the renewing of our minds (Rom. 12:2). True freedom is not found in redefining sexuality but in surrendering to the One who created it.