Is there a significant difference between changing your mind and doing penance? Absolutely.
When we think about what sparked the Reformation, the most common narratives focus on the emotional and spiritual distress that Martin Luther experienced as an Augustinian friar. The medieval Catholic system of infused grace and penance created constant uncertainty for Luther and countless other believers. However, emotional distress alone does not necessarily mean that what the Church was teaching was false. Thankfully, the Reformation was not merely a movement of emotions. Instead, Luther’s distress drove him outside of himself—to the text of Scripture.
In the words of Christ, the apostles, and the prophets, Luther found that the fear and uncertainty imposed by the Church were nowhere to be found. Not only was such distress absent, but Luther also discovered that Scripture had been blatantly misinterpreted to support the penitential theology being taught.
Perhaps the most famous turning point of the Reformation was the publication of the Ninety-Five Theses on the Castle Church door in Wittenberg in 1517. Our organization, 1517, takes its namesake from this historic event. The theses themselves begin with Matthew 4:17:
“From that time Jesus began to preach, saying, ‘Repent, for the kingdom of heaven is at hand.’”
Luther quickly pointed out that Church authorities had been mistranslating “repent” as “do penance” for nearly 1,000 years. This error, found in Jerome’s Latin Vulgate, was exposed in Luther’s lifetime thanks to the publication of Greek New Testament manuscripts by Desiderius Erasmus. The Greek word in question is μετάνοια (metanoia), a common term in the New Testament, meaning “a change of heart” or “a change of mind.” It is a compound word, with "meta" meaning ascend, go beyond, or change and "noein" referring to the mind, thought, or perception.
However, Jerome’s Vulgate had rendered metanoia as “paenitentiam agite,” which means “do penance.” Penance was taught as an act of punishment or atonement for sin, turning repentance into something to be accomplished through confession, satisfaction, and indulgences. In the second thesis of the 95 Theses, Luther directly refutes this:
"This word cannot be understood as referring to the sacrament of penance, that is, confession and satisfaction, as administered by the clergy."
Luther was not the only person to recognize this error. Erasmus corrected paenitentiam agite to resipiscite in his Latin translation of the New Testament. In the Ninety-Five Theses, Luther argued that this mistranslation had created an entire penitential system that undermined Christ’s atonement by adding man-made laws, which instilled unnecessary guilt and uncertainty in the hearts of Christians while consolidating power in the hands of the papacy.
Changing Your Mind vs. Doing Penance
Is there a significant difference between changing your mind and doing penance? Absolutely. The basic contrast lies between internal transformation and external actions.
The Latin verb ago (root of agite in paenitentiam agite) means "to put something into motion"— it conveys action. This is where we get the English word agitate. Thus, paenitentiam agite essentially commands: “Perform acts of penance” or more blatantly “Atone for your sins.” It assumes that humans have the power to satisfy the demands of the law, both God’s law and the additional demands of the pope and priests.
By contrast, metanoia (repentance) is not merely about external actions—it is a complete, internal change of heart, mind, and will. True repentance is not just fulfilling punishing tasks; it is a total transformation from sin, death, and self toward Christ. But who has the power to change the human heart?
True repentance is not just fulfilling punishing tasks; it is a total transformation from sin, death, and self toward Christ.
Scripture is clear: repentance is God’s work, not ours. Ezekiel 11:19 says, “And I will give them one heart, and a new spirit I will put within them. I will remove the heart of stone from their flesh and give them a heart of flesh.” Jeremiah 24:7 reinforces this, stating, “I will give them a heart to know that I am the Lord, and they shall be my people and I will be their God, for they shall return to me with their whole heart.” Likewise, Psalm 51:10 pleads, “Create in me a clean heart, O God, and renew a right spirit within me.”
God delivers this heart through the creation and sustaining of faith, which again is not a work of man but a gift from the Holy Spirit. Romans 10:17 says, “So faith comes from hearing, and hearing through the word of Christ.” Ephesians 1:13-14, “In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.” And again in 2 Corinthians 1:22, “And who has also put his seal on us and given us his Spirit in our hearts as a guarantee.”
The change of repentance is total, but the power of repentance is God’s, not man’s. The command paenitentiam agite assumes that humans have the ability to do works of atonement for themselves. But repentance which is an internal change of heart demands much more and is not something we can’t accomplish by any power inside of ourselves. Scripture teaches that repentance is God’s demand and God’s gift —granted and brought about by him—not a decision we make, but something we receive. It is for this reason that the Lutherans confess to this day that, “repentance consists of two parts: one is contrition or the terrors that strike the conscience when sin is recognized; the other is faith, which is brought to life by the gospel or absolution.”(AC XII, Kolb Wengert BoC) God uses his creative Word to accomplish both tasks: first through his law to reveal and condemn sin, and second through his gospel to bring life, comfort, a clean heart, and a right spirit.
The Reformation’s Key Doctrinal Divide
As the Reformation unfolded, it became clear that this mistranslation of repentance pointed to deeper theological errors within what would come to be called the Roman Catholic Church. The difference between God’s power to grant repentance and man’s effort to do penance is tied to foundational doctrines such as sin, grace, and the will. The totality of sin means that man is bound in sin and cannot free himself. Grace is not an infused power meant to fuel doing penance; it is instead God’s unmerited favor. The bondage of the human will teaches that the human will is enslaved to sin and incapable of turning to God but that God alone has the power to convert and sustain us. The penitential system suppressed these Biblical truths which ultimately obfuscated that the death and resurrection of Christ is the once-and-for-all atoning sacrifice for sin and the power of salvation to all who believe.
It was this seemingly small grammatical distinction—between metanoia and paenitentiam agite—which sparked the Gospel’s renewal in the Reformation. Luther’s discovery restored the Biblical proclamation: repentance is God’s work, not ours. And with that, the free forgiveness of sins in Christ was once again preached clearly.
