Fornication In All Of Its Forms Is Sin. “Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites... will inherit the kingdom of heaven.” (1 Corinthians 6:9). According to our earlier definition, four of the five sins mentioned here are actually “fornication”. We must flee fornication in all of its forms (1 Corinthians 6:18; Colossians 3:3-6).