Fornication

Fornication in Scripture denotes sexual immorality broadly, though the term carries different emphases in the Old and New Testaments. In the Mosaic law, it referred primarily to illicit sexual intercourse outside of marriage, condemned in both the covenant code and the holiness code (Leviticus 19:29; 21:9; Deuteronomy 22:20–21). The law treated fornication seriously as a disruption of family, inheritance, and covenantal holiness. The prophets also used fornication and adultery as extended metaphors for Israel's unfaithfulness to God through idolatry — "going after other gods" as a wife breaking the marriage covenant (Hosea 1–3; Jeremiah 3; Ezekiel 16; 23).

In the New Testament, the Greek porneia (from which derives the English "pornography") covers a wide range of sexual immorality including prostitution, premarital sex, adultery, incest, and homosexual acts. Paul lists it among the works of the flesh (Galatians 5:19) and singles it out with particular urgency: unlike other sins committed "outside the body," sexual immorality is a sin against the believer's own body, which is the temple of the Holy Spirit (1 Corinthians 6:18–19). The Jerusalem Council required Gentile converts to abstain from fornication alongside food offered to idols (Acts 15:20, 29). Revelation uses "fornication" figuratively for the great city's seduction of the nations into spiritual unfaithfulness (Revelation 17:2; 18:3).