The seven deadly sins are a list originally used in early Christian teachings to educate and instruct followers concerning fallen man's tendency to sin. The misconception about the list of seven “deadly” sins is that they are sins that God will not forgive. The Bible is clear that the only sin God will not forgive is that of continued unbelief, because it rejects the only means to obtain forgiveness—Jesus Christ and His substitutionary death on the cross.
Is the idea of seven deadly sins biblical? Yes and no. Proverbs 6:16-19 declares, “There are six things the LORD hates, seven that are detestable to him: 1) haughty eyes, 2) a lying tongue, 3) hands that shed innocent blood, 4) a heart that devises wicked schemes, 5) feet that are quick to rush into evil, 6) a false witness who pours out lies, and 7) a man who stirs up dissension among brothers.” However, this list is not what most people understand as the seven deadly sins.
According to Pope Gregory the Great in the 6th century, the seven deadly sins are as follows: pride, envy, gluttony, lust, anger, greed, and sloth. Although these are undeniably sins, they are never given the description of "the seven deadly sins" in the Bible. The traditional list of seven deadly sins can function as a good way to categorize the many different sins that exist. Nearly every kind of sin could be placed under one of the seven categories. More importantly, we must realize these seven sins are no more “deadly” than any other sin. All sin results in death (Romans 6:23). Praise be to God, that through Jesus Christ, all of our sins, including the “seven deadly sins,” can be forgiven (Matthew 26:28; Acts 10:43; Ephesians 1:7).