Reformation Day: Martin Luther and the Five Solas

Updated October 6, 2026.

Reformation Day is observed on October 31 to remember the Protestant Reformation and Martin Luther’s challenge to the sale of indulgences in 1517. The five solas summarize central biblical truths recovered during the Reformation: salvation is by grace alone, through faith alone, in Christ alone, according to Scripture alone, to the glory of God alone.

Why Is Reformation Day on October 31?

On October 31, 1517, Martin Luther sent Archbishop Albrecht of Mainz his Ninety-Five Theses concerning indulgences. The familiar account also places them on the door of the Castle Church in Wittenberg, Germany, although historians debate the details of that posting. His letter and theses challenged the false assurance people placed in purchasing indulgences.

The Ninety-Five Theses were points for debate, especially about repentance and indulgences; they were not a list of the five solas. The familiar fivefold summary developed later to express key convictions of the Reformation.

Many people associate October 31 with Halloween. As Christians, we can also use this date to remember the recovery of biblical teaching about salvation and ask whether our own confidence rests in Christ.

At the Diet of Worms in April 1521, after his excommunication, Martin Luther refused to recant unless convinced from Scripture. His answer contains one of my favorite statements:

Unless I am convinced by Scripture and plain reason – I do not accept the authority of the Popes and councils, for they have contradicted each other – my conscience is captive to the Word of God. I cannot and I will not recant anything for to go against conscience is neither right nor safe. God help me. Amen.

Martin Luther, Diet of Worms, 1521

In May 1521, Emperor Charles V issued the Edict of Worms, declaring Luther an outlaw and banning his writings. The decree prohibited people from giving him food, drink, or shelter. Luther’s stand had consequences far beyond an academic disagreement.

Jesus said, “I will build My church, and the gates of Hades shall not prevail against it.”

Matthew 16:18

It’s hard to argue that there are more significant fulfillments of this promise than the victory God produced through Martin Luther. When October 31st rolls around each year, we would do well to think not of Halloween, but of the Reformation and the Five Solas.

In honor of the Reformation, let’s consider what each of the five solas means and why these truths still matter.

What Are the Five Solas?

The Latin word sola means “alone.” These five phrases help us remember where our authority and our hope of salvation belong:

• Sola fide — faith alone: We are justified through faith, not by earning righteousness.
• Sola gratia — grace alone: Salvation is God’s undeserved gift.
• Sola Scriptura — Scripture alone: The Bible is our final authority for faith and practice.
• Solus Christus — Christ alone: Jesus is the only Savior and mediator between God and man.
• Soli Deo gloria — to God alone be the glory: God receives the praise for our salvation.

1. The Five Solas: Sola Fide—“Faith Alone”

Justification means being declared righteous by God. We receive this righteousness through faith in Christ, apart from works that could earn God’s acceptance. This is central to how Christianity differs from other religions: our hope rests in what Christ has done for us.

• Romans 4:5 To him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness.
• Ephesians 2:8-9 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.

Faith alone does not mean obedience is unimportant. Ephesians 2:10 follows the announcement of salvation by grace with God’s purpose for believers to walk in good works. Those works are the fruit of salvation, not the price we pay for it.

2. The Five Solas: Sola Gratia—“Grace Alone”

This excludes the works a person does to achieve salvation. Salvation comes by divine grace, or unmerited favor only, not from anything a sinner could do to earn God’s favor.

• Romans 3:24 Being justified freely by His grace through the redemption that is in Christ Jesus.
• Titus 3:5 Not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit.

3. The Five Solas: Sola Scriptura—“Scripture Alone”

This recognizes the Bible as our final authority for faith and practice. Pastors, councils, and traditions must be tested by God’s Word. Scripture alone does not mean teachers are useless; it means no teacher or church has authority to overrule what God has said.

• 2 Peter 1:20-21 Knowing this first, that no prophecy of Scripture is of any private interpretation, for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit.
• 2 Timothy 3:16-17 All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work.

4. The Five Solas: Solus Christus—“Christ Alone”

Jesus alone reconciles sinners to God through His sinless life, sacrificial death, and resurrection. We do not need another savior to complete His work. The Reformers emphasized Jesus as our High Priest and sole mediator, through whom we have access to the Father.

• 1 Timothy 2:5 For there is one God and one Mediator between God and men, the Man Christ Jesus
• Hebrews 4:15 For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin.

5. The Five Solas: Soli Deo Gloria—“To the Glory of God Alone”

This teaches that God, and not man, should receive all glory and honor. Rather than elevating Mary, the Pope, or saints, all praise and adoration should be reserved for the Lord exclusively.

• 1 Corinthians 10:31 Therefore, whether you eat or drink, or whatever you do, do all to the glory of God.
• Colossians 3:23 And whatever you do, do it heartily, as to the Lord and not to men.

The five solas direct us back to Scripture and to Christ. One of my favorite pictures of forgiveness received through faith is the paralytic who was lowered through the roof:

When He saw their faith, He said to him, “Man, your sins are forgiven you.”

Luke 5:20

We can’t do anything to obtain forgiveness, but it can be received by grace alone through faith alone in Christ alone. This is why a paralyzed man, who could do nothing but put faith in Christ, received forgiveness.

How to Observe Reformation Day as a Family

October 31 gives families an opportunity to do more than remember a date. We can open the Bible together and talk about the gospel. Here is a simple way to use this article for family worship or a small-group discussion:

• Read Ephesians 2:8–10. Ask: What does this passage say about grace, faith, and good works?
• Review the five solas. Let each person explain one in everyday language. Younger children can begin with the English meanings.
• Talk about Luther’s stand. Why should Scripture have the final word when a respected teacher or popular opinion disagrees with it?
• Apply the gospel personally. Are we trusting our behavior, religious activities, or family background to make us right with God—or trusting Christ?
• Pray together. Thank God for His grace and ask Him to help your family believe and obey His Word.

Reformation Day should turn our attention from confidence in ourselves to confidence in Christ. Remembering Luther is valuable when it leads us back to the Scriptures and to the Savior they reveal.