How do we know the purpose of the law according to the Bible?

According to Galatians 3:19, the law was added because of transgressions until the coming of Christ, the promised seed. It serves to reveal our sins, showing us our guilt before God and highlighting the necessity of redemption. Romans 3:20 states that through the law comes the knowledge of sin, affirming that it was never intended to be a means of salvation, but rather a tool to point us to Christ. In this way, the law functions as a schoolmaster, leading us to faith in Jesus so that we might be justified by that faith, as articulated in Galatians 3:24-25.