What is Sin?

Summary

The Psalm in front of us is one of the main penitential psalms in the Bible. Jews and Christians throughout history have often turned to Psalm 51 whenever we want to express our own personal sinfulness to God. “Have mercy on me, O God, according to your steadfast love. According to your abundant mercy, blot out my transgressions” (v. 1). It’s hard to improve on those simple yet heartfelt words. If you’re like me, then perhaps you’ve often prayed those words when your sin stares you in the face and will not let you go. Simply using the words of this psalm as your own prayer can do wonders for a sin-sick soul.

These are powerful words, and yet when you read this psalm carefully, you’ll see that it doesn’t say what sin the person committed. Did the person cheat a neighbor? Fail to make one of the sacrifices required by Jewish law? Commit adultery? Steal from the poor? Worship one of the Canaanite gods? We don’t know because the psalm doesn’t say. The only hint comes in verse 4, when the person says that “Against you [meaning God], you alone, have I sinned.” Whatever the sin was, the person feels it was a sin against God, rather than a sin against a family member, a friend, or someone else in the village.