Why do people resist the idea of salvation by grace alone?
People resist salvation by grace alone because it runs contrary to human thought. They want to do something and feel they have merited favor with God, but God will have none of it. Grace requires believing that God has finished it; adding Law or human effort perverts the Gospel and profits nothing.
Les explains that the Judaizers were trying to bring believers back under the Law, so Paul had to write Galatians with a constant warning: you are not under Law but under Grace, and no one should pervert the Gospel by adding something to it. Les sees the same bombardment today. He cites a letter claiming most people hate Paul's doctrines of grace; he would not put it that strongly, but knows people do not like it because most want to do something and feel they have merited favor with God. God will have none of it: either you believe He finished it, or it profits you nothing. This runs contrary to human thought, which is why grace alone meets resistance. Chronologically, Galatians was probably written a couple of years before the Corinthian letters; Paul's books are not arranged in the order written.