Is sex a sin?
Sex is not sinful, as long as it is within the confines of God's design for marriage. Sex is not something that mankind created; it is part of God's creation. He created sex for the purpose of reproduction and for pleasure. Yes, God created sex to be a pleasurable experience, otherwise it wouldn't be, and the human race probably wouldn't have lasted very long. In Genesis 1:28 God says to Adam and Eve, "Be fruitful and multiply and fill the earth and subdue it." After the flood, God said again to Noah and his sons, "Be fruitful and multiply and fill the earth" (Genesis 9:1). Procreation was a part of God's plan for mankind, and the method He designed for procreation is sex.As with so many things that God created good, the rebellion of mankind into sin has tainted what was once pure. Sin brings with it many desires that are selfish and contrary to God's commandments. As a result, we, as sinful and selfish human beings, often stray from God's plan for sex just as we do in other aspects of our lives. So sex can certainly be sin. However, again, within the union of marriage between one man and one woman sex is appropriate and encouraged. We've already seen God encourage, and even command, sex within marriage in Genesis. The Song of Solomon describes the pleasure of a married couple in their sexual relationship.
In the New Testament, Paul speaks on the subject when he wrote to the church in Corinth. He said, "The husband should give to his wife her conjugal rights, and likewise the wife to her husband. For the wife does not have authority over her own body, but the husband does. Likewise, the husband does not have authority over his own body, but the wife does. Do not deprive one another, except perhaps by agreement for a limited time, that you may devote yourselves to prayer; but then come together again, so that Satan may not tempt you because of your lack of self-control" (1 Corinthians 7:3–5). In Paul's use here, sex is presented as a marital obligation. When a husband and wife come together sexually, they become one flesh (Genesis 2:24); this is both a physical and a spiritual union that creates a deep emotional bond between the two. So, while Paul's point above is rather clinical, we should not forget that sex is one of the most intimate acts a man and woman can perform with one another, and the emotional and psychological impact of that act is far more profound than we often realize or admit. Within the marriage of one man and one woman, this can be a beautiful thing.
Now that last part of 1 Corinthians 7:5 is where we, as humans, get ourselves into trouble when it comes to sex. Not necessarily that a husband and wife are depriving one another, but that we lack self-control. In 1 Corinthians chapter 6 Paul writes, "The body is not meant for sexual immorality, but for the Lord" (1 Corinthians 6:13). First Corinthians 6:18 says, "Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body." Sexual immorality is any sex that is outside of God's intended design. That would include all sexual activity outside the marriage relationship of one man and one woman. Thus sex is a sin when it is in the context of things like premarital sex, adultery, sex with a child, sex with an animal, and sex with a person of the same biological sex (homosexuality).
All sin is harmful to us, and sexual sin is especially so (1 Corinthians 6:18). There is a deep emotional and psychological impact that sex has on a man and a woman. Within the context of a loving, heterosexual marriage relationship, this is a good thing. But sex outside of such a marriage causes more damage to our psyche and our emotional state than we realize. God's intent for sex was always for it to be a pleasurable experience which creates a bond between a husband and a wife and results in the continuation of the human race. In this way, there is nothing sinful about sex. Sex is only sinful when we pervert its good use by engaging in it outside of a heterosexual marriage.
Sexual sin is not outside of God's grace. If you have participated in sexual sin, there is forgiveness and healing available in Christ. First Corinthians 6:9–11 says, "Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God. And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God."
What is the purpose of marriage?
In marriage how do the two become one flesh?
Is there a difference between fornication and adultery?
Does the Bible say anything about sex addiction?
What does the Bible say about lust? What is lust?
Truth about Sin