“Ignorance of the distinction between the Law and Gospel is one of the principle sources of all the abuses which corrupt and still corrupt Christianity.”–Theodore Beza
“When we misunderstand the relationship between law and gospel, it leads to two opposite but equally destructive errors: legalism and license. Legalists continue to live under the law, believing that God’s approval is somehow dependent on their right conduct. Licentious people dismiss the law, believing that since they are “under grace,” God’s rules don’t matter much. These two errors have been around since the days of the apostles. The book of Galatians is written to combat the error of legalism: “Are you so foolish? Afer beginning with the Spirit, are you now trying to attain your goal by human effort?” (Gal. 3:3). The book of Romans addresses the error of license: “What then? Shall we sin because we are not under law but under grace?”(Rom. 6:15).
Both legalism and license are destructive to the gospel. To avoid these pitfalls, we must understand the biblical relationship between law and gospel. In a nutshell, here’s how God designed it to work: the law drives us to the gospel and the gospel frees us to obey the law. Realizing all that God expects of us should drive us in despair to Christ. And once we are united with Christ, the indwelling Holy Spirit causes us to delight in God’s law and gives us power to obey it.”— Bob Thune and Will Walker, The Gospel-Centered Life