What is legalism according to Les?
Legalism is the human idea that one must do something to earn God's favor. It appeals to the concept of self-effort, contrasting with Paul's doctrine that believers do nothing but rest on and believe what God has already finished on their behalf through Christ's death, burial, and resurrection.
Les teaches that legalism appeals to the human concept of "I have to do something." Paul's doctrine, by contrast, says we do nothing but rest on and believe what God says He has finished on our behalf. That, Les explains, is the Gospel—the death, burial, and resurrection of Christ. The letter of Galatians was written to refute false doctrine, which was primarily the inroads of legalism. Paul pointed out in Galatians 3 that believers did not come into their glorious position by law keeping but by faith, by believing the Gospel. Using Abraham as an illustration of faith, Paul says Abraham believed God, and it was accounted to him for righteousness. Les asks how much else Abraham did, and answers: nothing. He did not bring sacrifice, keep commandments, or get baptized in the Jordan; he did nothing but believe God.