Why is the law not sufficient for justification?

The law's role is to show us our inability to justify ourselves before God. In Galatians 2:16, Paul emphasizes that 'by the works of the law shall no flesh be justified.' The law demands absolute perfection, and since all have sinned (Romans 3:23), it cannot justify anyone. Instead, the law serves to reveal our sinfulness and point us toward the need for a Savior, hence the significance of Christ's redemptive work. The law was never intended as a means for justification but to lead us to Christ, the only one who could fulfill the law's requirements.