" The difference concerned only the logical--not even, perhaps, the temporal--order of three steps. Paul said that a man (1) first believes on Christ, (2) then is justified before God, (3) then immediately proceeds to keep God's law. The Judaizers said that a man (1) believes on Christ and (2) keeps the law of God the best he can, and then (3) is justified. "

― J. Gresham Machen , Christianity and Liberalism