They included exclusion from the covenant people (Leviticus 18:29, 20:17 - 18), childlessness (Leviticus 20:20 - 21) or even death (Leviticus 20:11 - 12, 14).
The church had a member who was having s** with his stepmother while his father was still alive (1Corinthians 5)! God's law enumerated differing penalties for those found committing incest. The apostle Paul had to grudgingly deal with a case of incest occurring in the church at Corinth. John the Baptist condemned the marriage of Herod Antipas to his brother Philip's wife (Mark 6:17), an act that was clearly a sin (Leviticus 18:16, 20:21). By the time of the New Testament, however, incest was strictly forbidden.
