The Bible provides a comprehensive framework regarding sexual relations, primarily found in the Old Testament, with reaffirmations and expansions in the New Testament. These laws are integral to understanding the biblical perspective on morality, purity, and the sanctity of marriage.

Old Testament Foundations

The foundational text for laws on sexual relations is found in the Book of Leviticus. Leviticus 18 and 20 outline various prohibitions and commandments concerning sexual conduct. These chapters emphasize the importance of holiness and separation from the practices of surrounding nations.

1. Prohibition of Incestuous Relationships: Leviticus 18:6-18 details prohibitions against sexual relations with close relatives, including parents, siblings, and in-laws. The text underscores the sanctity of family boundaries: "None of you are to approach any close relative to have sexual relations. I am the LORD" (Leviticus 18:6).

2. Adultery: Adultery is strictly forbidden, as seen in the Ten Commandments: "You shall not commit adultery" (Exodus 20:14). Leviticus 20:10 prescribes severe consequences for those who engage in adultery, reflecting the gravity of violating the marriage covenant.

3. Homosexuality: Leviticus 18:22 states, "You must not lie with a man as with a woman; that is an abomination" . This prohibition is reiterated in Leviticus 20:13, emphasizing the call to holiness and distinctiveness from other nations.

4. Bestiality: The Bible explicitly forbids sexual relations with animals, as stated in Leviticus 18:23 and 20:15-16. Such acts are considered perversions and are met with severe penalties.

5. Prohibitions Against Cultic Prostitution: Deuteronomy 23:17-18 warns against engaging in cultic prostitution, a practice associated with pagan worship. The Israelites are called to maintain purity in worship and personal conduct.

New Testament Affirmations

The New Testament reaffirms the Old Testament's moral teachings while emphasizing the transformative power of the Gospel. Jesus and the apostles address sexual immorality, calling believers to a higher standard of purity.

1. Marriage and Sexual Purity: Jesus reaffirms the sanctity of marriage in Matthew 19:4-6, quoting Genesis and emphasizing the union between a man and a woman. The apostle Paul echoes this in 1 Corinthians 7, advocating for sexual relations within the confines of marriage.

2. Condemnation of Sexual Immorality: Paul frequently addresses sexual immorality in his epistles. In 1 Corinthians 6:9-10, he lists those who will not inherit the kingdom of God, including the sexually immoral. He urges believers to flee from sexual immorality, highlighting the body as a temple of the Holy Spirit (1 Corinthians 6:18-19).

3. Call to Holiness: The New Testament calls believers to live holy lives, abstaining from sexual immorality. In 1 Thessalonians 4:3-5, Paul writes, "For it is God’s will that you should be holy: You must abstain from sexual immorality" .

Cultural and Theological Implications

The biblical laws on sexual relations reflect a broader theological narrative that upholds the sanctity of marriage, the importance of family, and the call to holiness. These laws serve as a guide for personal conduct and community standards, emphasizing the distinctiveness of God's people in a world with differing moral values.