Sola Scriptura: The Foundation of the Reformation

By Robb Brunansky

Published October 28, 2025

On October 31, 1517, Martin Luther nailed his 95 Theses to the door of the Wittenburg Church, igniting the Protestant Reformation. Luther was not trying to start a political or a spiritual revolution but attempting to begin a conversation about the theological problem of indulgences.

The sale of indulgences in the Roman Catholic Church originated, not as a spiritual matter, but as a civil one. In the Middle Ages, the church was the state, so it not only enforced theological, but civil, standards. Indulgences, then, were first instituted for criminals to pay for offenses against the state, increasing revenue and decreasing expenses. Initially, the church did not promise any spiritual benefit from these purchases.

Unfortunately, because church and state were one, this distinction between civic forgiveness and remission of guilt soon blurred into spiritual forgiveness and remission of guilt. The church saw how effective indulgences were in raising revenue for criminal activity, so they began selling indulgences for spiritual benefits. By the time Martin Luther came along nine centuries later, the sale of indulgences for spiritual benefit was rampant. Unsurprisingly, the more money Rome needed, the more “spiritually beneficial” indulgences became.

Martin Luther understood that true salvation through forgiveness of sins could not be purchased with perishable things (1 Peter 1:18-19). Luther therefore rightly condemned these sales and promoted the gospel of God’s grace, setting off a firestorm as Rome defended its stream of revenue.

Truly, at the heart of the Reformation stood the gospel. Four principles were developed to explain the gospel – the five solas of the Reformation. The first was sola gratia, which means ‘grace alone.’ We receive salvation because God freely chose to give it. Second was sola fide, which means ‘faith alone.’ Works cannot avail to justify sinners before a holy God.

However, how can we stand righteous before a Law that commands us to do (or not do) certain things only by faith and never by works? That is where we find solus Christus, Christ alone. Our salvation is based on His obedience, not ours. No human being can save or nullify our salvation; only Christ saves.

Soli deo gloria, then, logically and scripturally follows. If salvation is by grace alone through faith alone based on Christ alone, then we have no room for boasting. God alone deserves all glory for our salvation (Romans 11:36).

Now, this is all logically consistent. However, the Reformers were not creating a philosophical system but trying to see what Scripture taught about salvation. And the foundational principle supporting these solas was sola scriptura, Scripture alone. The basis for the Reformers’ arguments was not human tradition, church dogma, or papal edicts, but Scripture itself.

Now, that’s not to say they got everything right. The Reformers themselves disagreed over certain doctrines, such as baptism, the nature of divine election, and the Lord’s Supper. Their foundational principle, though, was that Scripture was the final authority.

The principle of Scripture alone was radical then, but it has always been controversial. The main issue with Scripture alone was not its necessity. Everyone agreed Scripture was necessary. The issue was its sufficiency. Do we need Scripture plus church tradition, papal edicts, or something else? Or do we need Scripture alone to understand God, salvation, and godly living? Do we believe in the power of Scripture to do what it says it will do? Most important, does the Scripture itself claim to be sufficient for everything necessary for life and godliness?

The Apostle Paul answered this question on death row in a Roman prison, to his protégé Timothy (2 Timothy 3:16-17). This was a daunting situation for Timothy. How would he know what to do without Paul’s wisdom? Paul gives Timothy a clear answer. Timothy must go to the Scriptures, which could sufficiently equip him for his God-given task. Timothy didn’t need Paul; he required God’s Word. Here lies the main point, that Scripture is sufficient to equip us for everything God has called us to do. The sufficiency of Scripture alone was Paul’s point to Timothy, and it is the Spirit’s to us as well. What we need to please God and obey Him, individually and corporately, is His Word. To see this, I want to look at three truths about Scripture from this passage.

First, we should comprehend the source of Scripture (verse 16a).

Paul tells us all Scripture is inspired by God. The Lord is the author of the entire Bible – not just parts of it. Scripture was breathed out by God and is the product of the Holy Spirit. The Bible we hold in our hands is not created from human ingenuity, opinion, philosophy, or creativity. It is the product of the mind of the eternal God.

Too easily, we are persuaded by human ideas, research, thinking, and opinions, and we neglect or reject God’s Word. Yet, we have the mind of God expressed in the Bible. Scripture stands alone as God-given and God-breathed. Everything else is a distant second.

Second, we must understand the usefulness of Scripture (verse 16b).

God has not given us some esoteric, abstract book of metaphysics. He has given us a word that is profitable, practical, and useful. None of His Words are impractical, irrelevant, out of date, or trivial – from Genesis 1:1 to Revelation 22:21.

Paul outlines four things Scriptures accomplishes. He first says Scripture is useful for teaching. What a person believes makes a critical difference in what they do and how they live. People who believe error do not receive truth. They have false doctrine, which condemns, leads to sin, and brings destruction. Christians, though, have been delivered from error. Scripture, then, is profitable for promoting a correct understanding of God, man, the world, Satan, salvation, judgment, and obedience.

Additionally, Paul says Scripture is useful for reproof. God’s Word demonstrates what is true and proves what is false. The New Testament writers often use Scripture in this double-edged way, constantly appealing to the Bible even within its pages! The third use Paul mentions is correction. Scripture is profitable for showing us where our conduct is sinful, ungodly, or wicked, and then correcting our conduct so we change direction. In conclusion, Paul says God’s Word is useful for training in righteousness. We need training, so we not only know what to do but are equipped to do it consistently.

For these things Scripture is profitable. God’s Word teaches us to discern truth from error, put off sin, and obey. It is eminently useful and practical.

Finally, we need to consider the purpose of Scripture (verse 17).

Scripture’s purpose equips us fully to live a godly life in a hostile world. The Bible is sufficient to teach us to do everything God has called us to do. If we are soaked in Scripture, we will be thoroughly trained to do God’s will.

There is one occasion when Scripture does not profit the church or the believer, which is when people reject it (Hebrews 4:2). If Scripture seems irrelevant, impractical, or impotent, the problem is not with God’s Word. Scripture only fails to profit when people do not believe what they read. Unbelief is the sole impediment to profiting from Scripture.

Evangelicals are heirs of the Protestant Reformation. There should be no doubt Scripture is our final authority in all matters of doctrine and practice. So, do we believe the Word of God? Is our hearing or reading of it mixed with faith? Do we believe it will teach, reprove, correct, and train us to do God’s will? Or are we looking to the opinions and ideas of mere men?

Sola scriptura is a wonderful foundation, but without faith, it is useless. Let us immerse ourselves in God’s Word, believe it, and be transformed by it.