Not living God's Commandments is sinning. If one knows what God's Commandments are, and deliberately does not obey, then he or she will never enter the kingdom of heaven.
(1 Corinthians 5:11) “What I wrote was that you should not associate with a brother Christian who is leading an immoral life, or is a usurer, or idolatrous, or a slanderer, or a drunkard or is dishonest; you should not even eat a meal with people like that.”
(1 Corinthians 6:9-19) “You know perfectly well that people who do wrong will not inherit the Kingdom of God: people of immoral lives, idolaters, adulterers, catamites, sodomites, thieves, usurers, drunkards, slanders and swindlers will never inherit the kingdom of God”
Also one who sins is not one of God’s Chosen.