Justification by faith alone is hard to summarize, but Thomas Schreiner does a good job when he describes Martin’s Luther’s view in his book, Faith Alone: The Doctrine of Justification (Zondervan, 2015):
God’s radical grace was necessary for human beings to be right before God because human obedience could never qualify….Believers needed an imputed righteousness, a righteousness given to them instead of earned by them….Faith receives what God gives, and those who put their faith in Jesus Christ as the crucified and risen one are right with God. (p. 52)
To those of us who are already convinced, this sounds great, but many who read these words will wonder why it matters. I understand the concern. The two little words faith alone have caused a lot of controversy, splitting the church between Roman Catholics and Protestants. Anything that divides the church must matter—even if only to expose the issue as a pointless discussion that divides the church—but the teaching of justification by faith alone brings us to the very heart of the gospel.
In the introduction to his book, Schreiner explains it this way: “We are talking about standing before God on the last day, on the day of judgment, and sola fide [faith alone] answers that question: How will we stand before the Holy One of Israel?” (16). Justification by faith alone “reminds us of the grace of the gospel, testifying that ultimately our salvation, our standing and acceptance before God, is entirely of the Lord” (17). Schreiner captures the issue at stake: justification by faith alone is a matter of eternal consequence.
Here I want to develop what he touches on. I want you to see that justification by faith alone matters not just for eternity but also for the present. It makes a difference in how we relate to God and people.
1. Justification by faith alone kills pride.
According to the apostle Paul, justification by faith alone excludes human boasting:
Then what becomes of our boasting? It is excluded. By what kind of law? By a law of works? No, but by the law of faith. For we hold that one is justified by faith apart from works of the law. (Rom. 3:27–28)
To be justified by faith alone is to be justified apart from human obedience, works, or worth. This means that Christians have nothing to take pride in, nothing to boast of, nothing to glory in except God. In justification by faith alone, God gets all the glory because God is the one who saves. In fact, when Paul explains justification by faith alone, it is against the backdrop of universal, human sinfulness (Rom. 3:9–20). This kills pride.
2. Justification by faith alone gives assurance.
According to the apostle Paul, justification by faith alone gives confidence in God. He calls it peace. He describes the Christian state as one of rejoicing:
Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God. (Rom. 5:1–2)
We who trust in Christ alone for salvation are justified by faith alone, and as the justified, we can have assurance. Our salvation does not depend upon our works, efforts, or good intentions, but on God alone, and this salvation is secure in Christ. Because it depends upon God alone who is faithful, we can have assurance that no matter what life looks like, or feels like, God will keep his promise to save us. Justification by faith alone gives assurance.
3. Justification by faith alone makes the Christian life possible.
According to the apostle Paul, justification by faith alone leads to a life of worship:
I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your Spiritual worship. Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect. (Rom. 12:1–2)
Martin Luther famously said, “A Christian is a perfectly free lord of all, subject to none. A Christian is a perfectly dutiful servant of all, subject to all.” Martin Luther wrote The Freedom of a Christian in 1520 after having come to a clear understanding of justification by faith alone, and then having to defend it.
The charge was, and always is, that justification by faith alone creates lazy people who are free to live as they please with complete disregard for holiness. Martin Luther argues the case that it is Christians—who no longer strive to merit salvation—who are actually free to do good. He draws upon the apostle Paul’s own reasoning in the book of Romans, which, after teaching justification by faith alone, continues to explain the work of the Holy Spirit and good works in the life of a Christian.
4. Justification by faith alone is true.
Justification by faith alone only matters if it’s true. The apostle Paul is very clear:
For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. (Rom. 3:23–25)
You won’t find the words “faith alone” in Scripture, but you will find the meaning. Every time Scripture contrasts faith and works, law and gospel, grace and condemnation, Paul is teaching that justification is received by faith alone and that salvation is a free gift.
The following are some resources I highly recommend to help you better understand the doctrine of justification by faith alone:
- Thomas Schreiner, Faith Alone: The Doctrine of Justification is helpful, accessible, and clear.
- J.V. Fesko, Justification: Understanding the Classic Reformed Doctrine (P&R Publishing, August 2008). I love this book by my former professor, and through the years Dr. Fesko has become a good friend. In this book he gives more than enough to satisfy questions, doubts, and geek-driven obsessions.
- Martin Luther’s treatise, The Freedom of a Christian is a classic (included in Martin Luther’s Basic Theological Writings [Fortress Press, 1989]). Martin Luther thought a lot about salvation and here does his best to work out how faith and works relate in the Christian life.
- Martin Luther’s Against the Antinomians is another great work (Martin Luther’s Basic Theological Writings [Fortress Press, 1989]). Here Martin Luther shows the importance of the Holy Spirit’s work in the Christian life and how this relates to justification by faith alone.
 (Martin Luther, “The Freedom of a Christian,” in Martin Luther’s Basic Theological Writings, ed. Timothy F. Lull, 2nd ed. [Fortress Press, October 1989], 386).