The term for “alienated” means “estranged,” “cut off,” or “separated.” Before they were reconciled, all people were completely estranged from God (Ephesians 2:12,13). The term for “enemies” can also be translated “hateful.” Unbelievers hate God and resent His holy standard because they love “wicked works” (John 3:19,20; 15:18,24,25). Actually there is alienation from both sides, since God “hates all workers of iniquity” (Psalm 5:5). Christ’s substitutionary death on the cross that paid the full penalty for the sin of all who believe made reconciliation possible and actual (Romans 3:25;5:9,10;8:3).
Commentary from the MacArthur study Bible, notes for Colossians 1:21.