The Scriptural truth of justification by faith alone is the teaching most closely associated with Martin Luther. It was a radical change from the idea that justification would only take place in the future on the day of judgement. Even more radical was the truth that it was by faith alone and not faith formed by acts of charity that would merit eternal life. Luther saw that Scripture teaches that we are not justified by any work that we do but solely on the basis of the imputed righteousness of Christ (Romans 3:21; 4:4-5). No wonder he wrote: “One cannot go soft or give way on this article, for then heaven and earth would fall”.
He also wrote that justification is “the most delightful” doctrine. But he added, that there were “few…who have thought it through well and who teach it aright”. About 150 years later it still needed correct teaching and thinking. John Brown of Wamphray wrote The Life of Justification Opened in order to clarify the doctrine against those who were introducing error. This problem remains today. One of the areas that Brown discusses is how faith justifies:
Faith is looking to Christ, as the stung Israelite in the wilderness looked to the brazen serpent (John 3:14,-15). Faith is saying ‘In the Lord have I righteousness’ (Isaiah 45:24). It is the believer putting on the Lord Jesus, that he may be found in Him and clothed with His righteousness (Philippians 3:9). It is receiving Christ (John 1:12) and receiving the atonement in Him and through Him (Romans 5:11) together with abundance of grace and the gift of righteousness (Romans 5:17). It is therefore called ‘believing on His name’ (John 1:12; 6:29; 7:35; 17:20; Acts 16:31; 19:25). Because faith has laid hold on this righteousness of Christ, this righteousness is called the ‘righteousness of faith’ (Romans 4:11) and the ‘righteousness which is of faith’ (Romans 9:30). It is that, ‘which is through the faith of Christ, the righteousness which is of God by faith’ (Philippians 3:9). Justifying faith is receiving Christ and His righteousness. It takes the man out of himself so that he may find and partake of that all-sufficient righteousness of Christ. Thus he may stand before God with confidence and expect pardon and acceptance. To say that faith is itself the gospel-righteousness on which they may lean and expect justification would be to destroy the essential work of justifying faith.
Brown emphasises that believers are not justified on account of their faith, as if that constituted their “gospel-righteousness”. Rather they are only justified on account of the righteousness of Christ imputed to them through faith as a mere instrument or means of receiving it. He continues:
Faith, in this matter, is as the eye of the soul, that does not look to itself but looks out to another. All who would live the life of justification must take themselves to Jesus Christ, lean on Him and His righteousness. They must be clothed with the robe of His righteousness alone and found in Christ alone. This is the only basis on which they must think of standing before God, having on Christ’s righteousness which God imputes to believers, and which they receive by faith, in order that they may have justification.