The first practical application of the doctrine of justification by faith alone is assurance. Frankly, there will be days when we simply won’t feel justified, when we won’t feel like a Christian. We will have off days, down days, shaky days, sinful days, days on which the question haunts our minds, “Am I even a Christian?” The doctrine of justification by faith alone proclaims loudly, through the fog of doubt, that we have been born again and are “in Christ” (Gal. 2:20). Christ has completed His redemptive work, satisfied the justice of God the Father, and sealed us with His Holy Spirit. Justification assures us that there is never a need for re-justification. Rather, God justifies us by His grace. Before the courtroom of heaven, God has declared us, depraved sinners, to be “justified and righteous.” Paul declares, “Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ” (Rom. 5:1). The doctrine of justification gives us the assurance to know that “[He is] just and the justifier of the one who has faith in Jesus” (3:26). When we have those down days, or we feel insecure, we can refresh our hearts by drinking at the everlasting fountain of justification by faith alone and can hear God saying, “You are in Christ and shall remain in Christ forever.”
At the end of Romans 8, Paul argues: “Who shall bring any charge against God’s elect? It is God who justifies. Who is to condemn?” (vv. 33–34a). By God’s grace, justification protects and defends the believer against any accusation of the enemy. When Satan attacks and accuses us, when he tries to knock out the foundation upon which we are firmly planted, when he tries to convince us that our sins are too great, or when he says, “God has surely not said you are actually saved,” let us remind ourselves, with the authority of Scripture: “God has declared me righteous. I have nothing to offer or give to God, for there is nothing righteous inherently within me, but God is the One who justifies; who can condemn?” Peter advises in 1 Peter 5:9, “Resist [the devil], firm in your faith,” and he will flee from you. When we are accused, when we are tempted to doubt, when accusation is brought against us from the great enemy of our souls, let us flee to the high tower of justification by faith alone and find solace and refuge in God who accepts us through His only begotten Son.
In Ephesians 2:8–9, Paul declares that it is “by grace [we] have been saved through faith. And this is not [our] own doing; it is the gift of God, not a result of works, so that no one may boast.” Salvation is not our own doing. Why? Paul tells us it is so that “no one may boast.” If we are justified by faith alone, there is nothing in which we can boast. Rather, a proper apprehension of the grace of God in justification should cultivate nothing in us but humility. When we properly grasp what God has done for us, there is no room for pride. In fact, our response should be quite the opposite. Knowing that God has removed our sins, placed our sins on His own Son, imputed His Son’s righteousness to our accounts, and declared us righteous through the merit of His Son should humble our hearts like no other truth on this earth. In Romans 3, the Apostle Paul expounds on this humbling doctrine by asking, “Then what becomes of our boasting?” (v. 27). It’s almost as if Paul takes us by the shoulders, looks us deeply in the eye, and says: “Where is it? Where is your boasting? It is excluded. There is no boasting here.” Paul would say a prideful Christian is a contradiction in terms. Justification is all of grace, not a grace of our own, but the unmerited grace of God. Therefore, any boasting, any praise, any glory must go to Him and Him alone.
Having a biblical view of justification should also produce overwhelming thanksgiving. Knowing that justification by faith is apart from works, that justification is a gift of God, and that we are pardoned, declared righteous, and adopted into the family of God should generate within us a heart of eternal thankfulness. This thankfulness then translates into a life of consistent worship of the God, who, in His infinite wisdom, devised a way that depraved sinners might be accepted in the Beloved. The truth of justification by faith should cause all believers to join their voices with the angelic hosts and cry out before God, “Holy, holy, holy is the Lord God almighty.” If our view of justification does not generate a life of worship and thanksgiving, then our view of justification is wanting. But, if we have believed the promises of God, if we have believed He has sent His Son for us and died as our substitute, if we have confessed and repented of our sin, we are justified. Praise Him!
Justification by faith alone is not merely for debate and theological discussion; it has real implications in the lives of all believers. When we properly understand this doctrine, we properly know assurance, have a defense against our common enemy, develop a heart of humility, and live a life of continual thanksgiving.