We live in a culture where the concept of sin has become entangled in legalistic arguments over right and wrong. When many of us consider "What is sin?" we think of violations of the Ten Commandments. Even then, we tend to think of murder and adultery as "major" sins compared with lying, cursing, or idolatry.
God wants us to recognize our sins, sin is the rupture of the covenanted relationship between God and his people.
Tragically, sin in any amount will distance us from God.