Incest

Sexual relations between close relatives.

Prohibitions against incest are prominent in Leviticus 18. Leviticus 20 also addresses the matter and attaches the death penalty to certain kinds of incest. The assignment of severe penalty and the judgments of dishonor and perversion clearly mark incest as a grave offense.

Actual cases in the Bible show incest to be the fruit of a flawed character. Lot’s daughters slept with their drunken father and both became pregnant (Gn 19:30-38). And in 2 Samuel 13:1-22, the deceitful Amnon showed no shame in forcing himself upon his half sister Tamar. Paul’s strong rebuke in 1 Corinthians 5:1-5 demonstrates that neither the act nor its wickedness is limited to OT times.

Blood relationship, or consanguinity, is one ground for declaring sexual contact unlawful. This applies, for example, to brothers and sisters, parents and children, grandparents and grandchildren, as well as some aunts, uncles, nieces, and nephews.

The relationships denounced in Leviticus 18 are not, however, all based upon blood kinship. A number of them are matters of kinship through marriage, matters of affinity. In this connection, sexual relations with in-laws and certain aunts and uncles are declared incestuous. It should be noted that the in-law rule could be relaxed in ancient Israel when a widowed sister-in-law was left without a son (Dt 25:5-10).

While there are good genetic reasons to shun incest among blood relations, the fundamental problem with incest is that it strikes at the soundness of the family. And since the family is central to God’s purposes and work on earth, his judgment on this practice is fierce. Families simply cannot survive sexual intrigue among their members.