What does the Bible say about lack of sex in marriage?

from the old testament

• God's created order was for a man and woman to join in a marital covenant, which included the sexual union: "Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh" (Genesis 2:24). Sex is meant to be a part of marriage.
• Marital duty included meeting sexual needs: If he takes another wife to himself, he shall not diminish her food, her clothing, or her marital rights (Exodus 21:10). Even in the Mosaic law, spouses were not to neglect each other’s marital rights, which includes sexual responsibility within marriage.
• The Song of Solomon celebrates romantic love and the sexual intimacy that is part of marriage. The book presents sex as joyful.
• In warning against adultery, a father advises his son to "rejoice in the wife of your youth" (Proverbs 5:18). When a marriage is sexless, that leaves the door open to temptation.
• Marriage is meant to prevent sexual deprivation. This is why Proverbs 15:5 tells us to “drink water from your own cistern, flowing water from your own well.” Sexual intimacy is meant to be enjoyed within marriage, not withheld or sought elsewhere.
• Exodus 19:15 and Leviticus 15 show that abstaining from sex within marriage was meant to be temporary and for specific ritual purification reasons.

from the new testament

• Paul's first letter to the Corinthians lays out the intimiate obligations that each spouse has to each other: "The husband should give to his wife her conjugal rights, and likewise the wife to her husband" (1 Corinthians 7:3). Lack of sex in marriage creates distance and opens the door to sin. Instead, we are to cultivate sexual intimacy in marriage.
• Paul continues to instruct husbands and wives not to "deprive one another, except perhaps by agreement for a limited time, . . . so that Satan may not tempt you because of your lack of self-control" (1 Corinthians 7:5). Sexual abstinence within marriage is meant to only temporary and mutual for a specific purpose. After the limited time, husbands and wife should "come together again,” that is, have sex again.
• Marriage includes regular physical intimacy as protection against temptation. First Corinthians 7:2 states, “Because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.” Sexual intimacy within marriage is given as a safeguard against temptation and unfaithfulness. That does not mean that having a sexless marriage gives you permission to give into temptation and unfaithfulness. It is just a warning that if a marriage is sexless, the husband and wife should address what is causing it so the opportunity for sin is less.

implications for today

A new pair of shoes. Deciding what to say to someone who has lost a loved one. Driving your spouse's car (adjusting the seat and mirrors). Some things make us a little uncomfortable. Talking about sex is one of them—ironic for our hypersexualized society. But the topic shouldn't be ignored, especially when problems arise with it in Christian marriages.

They say a sexless marriage is a symptom of bigger problems. Unaddressed hurts build up and show up as lack of physical intimacy. Or it might just be hectic schedules that leave husbands and wives too drained to do more than sleep. But Christian marriages shouldn't allow sexlessness to take root. Satan is all too ready to use that weakness.

If the sexlessness is masking a deeper problem, couples should pray about it, talk about it, and seek Christian marital counseling. What they shouldn't do is just ignore it. Sex within marriage is God's gift, one that shouldn't be disregarded. And in marriage, even the most uncomfortable conversations are often the ones that protect what God intended to be held together.