It is not difficult to find people who will criticize the Christian sexual ethic as repressive and even hateful, invented in order to control other people and maintain the status quo. Such claims display historical ignorance. Christianity was born in a world where men, married or single, could generally do what they wanted sexually and that offered no protection to women from abuse. By making sexual activity lawful only within the one-man/one-woman marriage relationship and teaching that the body of a husband belonged to his wife (1 Cor. 7:1–9), Christianity actually freed women from being mere sexual objects and released people from slavery to their sexual desires.
Moreover, the Christian sexual ethic was no invention of human beings. As Paul makes clear in today’s passage, to disregard the Apostolic and prophetic teaching on sexual immorality is to disregard God Himself. True, the Scriptures were written by human beings, as its teachings on ethics, theology, and other matters come through the Apostles and prophets. However, what they wrote and taught was not the words of men but was and is the words of God (1 Thess. 4:8). Anyone who rejects the teaching of Paul and the other Apostles on human sexuality is rejecting God Himself.
Thus, one cannot be a Christian and believe the world’s false narratives about human sexuality or embrace a sexual ethic that approves of homosexuality, heterosexual fornication, bestiality, pornography, incest, adultery, pedophilia, premarital cohabitation, polygamy, or anything else forbidden by the Lord in His Word (Lev. 18; 1 Cor. 5; 6:9–11; 1 Thess. 4:3–7). This is not to say that it is impossible for Christians to commit sexual sin. Believers can and do fall into all types of sin, including violations of God’s sexual ethic. And thanks be to God, there is forgiveness for all types of sin, including sexual transgressions, when we trust in Christ and renounce our evil ways (1 John 1:8–9). But those who have been converted to Christ do not approve of sexual sin or seek to change the biblical ethic. They embrace the Bible’s teaching, even while recognizing that they fall short of it. Anyone who professes Christ and rejects God’s Word on sexual matters does not have the Holy Spirit and thus is not a true believer (1 Thess. 4:8). If we want to please God, we must keep His moral law. And if we do not want to keep His moral law, we do not want to please Him and cannot call ourselves Christians.