What Is Conversion?


Conversion begins with the gracious gift of new life and gives rise to a genuine faith and repentance that continue throughout the Christian life.


This essay surveys the history of the doctrine of conversion from the early church to the present time, the Old and New Testament data surrounding the term and its usage, theological statements such as the Heidelberg Catechism and the Westminster Confession, and practical differences of this broader perspective of conversion with the revivalist usage of the term.


Anyone who has traveled abroad understands that currency must be converted from that of one system to that of another. American travelers to Israel must convert US Dollars to Shekels, and Israeli travelers to Europe must convert Shekels to Euros. We speak of converting computer documents from one format to another. Marketing and business experts speak of converting potential clients into paying customers. At that level most Christians have an intuitive sense of what Luke means in Acts 15:3 when he speaks of the “conversion [epistrophēn] of the Gentiles.”


As with many things, however, conversion is not as simple as it seems at first. Embedded in this concept are connections to several Christian doctrines. The doctrine of conversion touches the doctrines of effectual calling, regeneration, sanctification, and repentance.


Since the middle of the nineteenth century it has been the convention of many evangelicals to think and speak of conversion as something that takes place in a single, critical event. This approach to conversion is so widely held that scholars speak of a “conversionist” approach to subjects. For example, writers from this tradition look for external evidence of one has had a “conversion experience.”

In the early post-Apostolic Church, however, the language of conversion tends to refer less to a single, critical event and more to a process or an outcome. For example, 1 Clement 18:13 quotes Psalm 51:13 “I will teach the lawless your ways, and the impious will convert to you” (50:15 in the LXX) not to illustrate a single decisive event but as part of an extended call to the Corinthian congregation to repent and stop fighting with one another. In the earliest recorded post-Apostolic Christian sermon, 2 Clement 17:2 addresses conversion in the context of his third call for repentance. It is synonymous with mutual admonition: “let us help one another to restore the weak toward the good so that we might save all; let us also convert (epistrepsōmen) one another and correct one another.” The authors of 1 and 2 Clement did not imagine that we have the power to bring our brothers and sisters to new life but we can help them in their progress toward godliness. We see a similar way of speaking in the Shepherd of Hermas (3:1), where the elderly woman (in Hermas’ bizarre vision) remonstrates with him that God is angry with him “in order that you may convert (epistrepsēs) your household.” In context, the idea is not an initial regeneration from spiritual death to life but rather it is that he has failed to “correct” his family. Hermas uses a word here from the same semantic family as occurs in 2 Clement in this connection.

In the third century, the North African pastor Cyprian of Carthage (d. AD 258) spoke of the conversion of thousands heretics around Carthage to the church and to orthodox Christian belief and practice. In this usage, the verb to convert signals a fundamental change of religious belief and practice. It is in this sense that the church has often spoken of “converts from paganism” or “converts from Judaism” and the like. This is the sense in which Augustine (AD 354–430), in his Confessions (13.1) spoke of being converted out of Manichaeism to Christianity.

In the Reformation, the Protestants taught the necessity of repentance not as an antecedent condition in order to be saved, as if repentance is a work that must be done either on the grounds of which or through which one is saved. Rather, as Calvin’s student Caspar Olevianus wrote, “One receives Christ and his imputed righteousness through faith alone, and with Christ’s righteousness one also receives the Spirit of sanctification who renews one to repentance, i.e., the putting to death of the old life and making alive of the new man.” According to the Reformed, faith and repentance are united but distinct. Saving faith has as its object Christ and his righteousness. Repentance is recognition of one’s sin and a consequent a change of mind and life born of new life and true faith.


The principal Old Testament word for conversion (Shub), in its most basic usage, means “to return” or “to go back.” It can signal the sense of changing one’s mind and in some forms can refer to being brought back to a place or a state. 1 Kings 8:48 is a clear example the use of this verb to mean repentance, i.e., turning away from sin and turning in faith to Yahweh: “if they repent with all their heart and with all their soul in the land of their enemies, who carried them captive, and pray to you toward their land, which you gave to their fathers, the city that you have chosen, and the house that I have built for your name….” Isaiah 6:10 uses this same verb in a similar context and to the same effect: “…lest they hear with their ears and understand with their hearts and repent and be healed.” In John 12:40, our Lord Jesus quoted this very verse in reference to the Jews of his day.

In the New Testament there is a range of terms that get at the concept of conversion. Acts 13:43 refers to proselytes – converts to Judaism – who were interested in Paul’s teaching. In 1 Timothy 3:6 Paul warns Timothy against ordaining neophytes, i.e., recent converts to Christianity to the pastoral office. In Romans 16:5 Paul speaks metaphorically of Epaenetus as the “first fruits” (aparchē) of his ministry in Asia Minor. This noun is often translated in the New Testament and the Apostolic Fathers (e.g., 1 Clement 42:4) as “convert.”

The Old Testament idea of conversion as “turning” is present in Matthew 18:3, “And he said, ‘Amen, I say to you, unless you are converted (straphēte) and become as children you will not enter into the Kingdom of Heaven.’” In this case, because the verb is in the passive voice, it seems clear that it is the Lord himself who turns his people to himself.

The New Testament verb “to turn” (metanoeo) and its related noun (metanoia) serve the same function as the Old Testament language. When John the Baptist says, “repent, for the Kingdom of God is at hand” (Matt 3:2), it is a call to acknowledge sin and turn from it in faith to Jesus the coming Messiah. When Jesus proclaimed, “The Kingdom of God is at hand, repent and believe the gospel” (Mark 1:15), it was a call to acknowledge the greatness of one’s sin and misery and to turn in faith to him. Jesus indicated as much when he referred to the repentance and faith of the people of after they heard Jonah’s message (Matt 12:41). In Acts 2:38, in response to the query from men at the Feast of Pentecost, Peter proclaimed, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins….” Paul says that he preached the necessity of the acknowledging and turning from sin and to Jesus (Acts 26:20). Peter wrote that God is patiently calling all of his elect out of the world “not willing that any should perish but that all should come to repentance” (2 Pet 3:9).

Repentance is something that Christians continue to do after their initial turning to the Lord. In Luke 17:3 Jesus says that if a brother sins against one seven times in a day but repents seven times, he must be forgiven. In 2 Corinthians 7:10 Paul says, “For godly grief produces a repentance that leads to salvation without regret, whereas worldly grief produces death.” The letters to the Seven Churches in the first three chapters of the Revelation are largely a call to repentance on the model of call by the Old Testament prophets to Israel and Judah. Thus, repentance is an essential aspect of the beginning of the Christian life and also its ongoing development. In short, insofar as conversion encompasses turning and repentance, it is a lifelong process.


We might distinguish between two types of conversions in Scripture: external and internal. True conversion is the work of God’s sovereign grace in the human heart. In the Heidelberg Catechism the Reformed Churches equated “true repentance” with “conversion” (Heidelberg Catechism, 88):

In how many things does true repentance or conversion consist?

In two things: The dying of the old man and the making alive of the new.

The traditional language for the dying of the old man is mortification and the making alive of the new is called vivification. The former is defined as “heartfelt sorrow for sin, causing us to hate it and turn from it always more and more” (Heidelberg Catechism, 89). The latter is “heartfelt joy in God through Christ, causing us to take delight in living according to the will of God in all good works” (Heidelberg Catechism, 90). In short, the Christian life is a life of being converted daily.

The Westminster Divines confessed the same definitions and doctrines but added, however, that humanity, by Adam’s fall into sin, by nature is unable and unwilling “to do any spiritual good.” The effects of the fall are such that fallen sinners are unable to convert themselves or even to prepare themselves for conversion (Westminster Confession of Faith, 9.3). It is God who “converts a sinner” and who “translates him into a state of grace” thereby freeing him from his “natural bondage under sin…by grace alone” and “enables him freely to will and to do that which is spiritually good.” Because of our remaining corruption in this life we are never perfectly converted (WCF, 9.4). Against the Remonstrants (Arminians), the Reformed Churches of Europe and the British Isles confessed at the Synod of Dort that conversion is unconditional gift of God to his elect. They rejected the Arminian doctrine that grace is resistible and that one who is truly converted might thereby be lost.

Scripture does record for us examples of those who were outwardly part of the visible church, whether under the Old Testament types and shadows or under the New Testament. In the Parable of the Sower (Matt 13:20–21) Jesus warned that the external administration of the gospel (the sowing of the seed) is one thing but its reception is another. There will be those who seem to believe but who have no root in Christ, who have only temporary faith (as distinct from true faith), and who fall away under adversity. The Old Testament is replete with examples of such (e.g., 1Kgs 19:18; Rom 11:4–5). The minor prophets excoriated the visible people of God for honoring God with their lips but not with their hearts (e.g., Isa 29:13). In the New Testament we see members of the visible church, Ananias and Sapphira, who were not actually converted and thus lied to the Holy Spirit and were put to death by the Holy Spirit (Acts 5:1–11). Judas was a member of the company of the disciples but betrayed our Lord for 30 pieces of silver (Matt 27:9; Acts 1:25). Hebrews 6:4–6 warns that there can be those who participate in the external life of the church (“tasted of the goodness of the Word and of the power of the age to come”) and yet who fall away because they are not actually converted. These, Hebrews says, have “trampled underfoot the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace” (Heb 10:29). Hymenaeus and Alexander “made shipwreck of their faith” (1 Tim 1:19–20) and Philetus “swerved from the truth” by teaching falsely that Jesus had already returned.


The biblical, ancient Christian, and Reformation understanding of conversion is at odds with the model of conversion that has predominated among contemporary evangelicals. That model was fueled by the Pietistic reaction to a perceived spiritual coldness in the state churches in Europe. Immigrants to the New World brought that reaction with them. The theology 18th century revivals (“the First Great Awakening”) was monergistic but it focused on discernible episodes and evidence of conversion. The revivals that dominated in the 19th century (“the Second Great Awakening”) tended to be Arminian and synergistic in theology and external evidence of a decisive conversion event became even more important as revivalists such as Charles Finney (1792–1875) perfected the system of the “anxious bench.” Versions of this approach persisted through the work of Dwight L. Moody (1837–99), Billy Sunday (1862–1935), Sister Aimee Semple McPherson (1890–1944), and Billy Graham (1918–2018).

In contrast to the Modern revival traditions we should better think of conversion as beginning with the gracious gift of new life (John 3:1–12) that gives rise to a genuine faith and repentance that continue throughout the Christian life as the believer trusts the Lord, lives in union with risen Christ, in the visible church, attending to the preaching of the Word, prayer, making use of the sacraments, and seeking to be brought into conformity daily with the Savior by the gracious renewing work of the Holy Spirit.


  • Augustine of Hippo. “The Confessions of St. Augustin,” in The Confessions and Letters of St. Augustin with a Sketch of His Life and Work, ed. Philip Schaff, trans. J. G. Pilkington, vol. 1, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (Buffalo, NY: Christian Literature Company, 1886.
  • Berkhof, Systematic Theology. Grand Rapids: Wm. B. Eerdmans Publishing, 1938.
  • Calvin, John. Commentary on the Book of Psalms, trans. James Anderson. Grand Rapids: Eerdmans Publishing, 1948.
  • Clark, R. Scott. Caspar Olevian and the Substance of the Covenant: The Double Benefit of Christ. Grand Rapids: Reformation Heritage Books, 2008.
  • Clark, R. Scott. “‘Magic and Noise:’ Reformed Christianity in Sister’s America,” in eds. R. Scott Clark and Joel E. Kim. Always Reformed: Essays in Honor of W. Robert Godfrey. Escondido: Westminster Seminary California, 2010.
  • Cyprian of Carthage, “The Epistles of Cyprian,” in Fathers of the Third Century: Hippolytus, Cyprian, Novatian, Appendix, ed. Alexander Roberts, James Donaldson, and A. Cleveland Coxe, trans. Robert Ernest Wallis, vol. 5, The Ante-Nicene Fathers. Buffalo, NY: Christian Literature Company, 1886.
  • Hatch, Nathan O. The Democratization of American Christianity. New Haven: Yale University Press, 1989.
  • Holmes, Michael W. The Apostolic Fathers. Greek Texts and English Translations. Grand Rapids: Baker Academic, 2007.
  • Malony, H. N., s.v., “Conversion,” in Geoffrey W. Bromiley, The International Standard Bible Encyclopedia, Rev. Wm. B. Eerdmans, 1979–88. Schaff, Phillip, ed. The Creeds of Christendom. Grand Rapids: Baker, 1983.

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Some minor typographical corrections have been made to this text. Thanks to M. J. Denning and Keith Giles for their editorial help.



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    R.Scott Clark is the President of the Heidelberg Reformation Association, the author and editor of, and contributor to several books and the author of many articles. He has taught church history and historical theology since 1997 at Westminster Seminary California. He has also taught at Wheaton College, Reformed Theological Seminary, and Concordia University. He has hosted the Heidelblog since 2007.

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  1. It’s hard to break from the evangelical and revivalist mindset. This is a helpful outline of the Scriptural understanding of conversion.

    One small typo remains..in Theology section, third paragraph beginning ‘The Westminster Divines’, 5th line…it reads “converts and sinner”, should be “converts a sinner”

    (And later should there be a ‘with’ in ‘the Old Testament is replete examples of such’?

  2. Dr. Clark

    I am a young Christian and I am having a rough time with the warning passages in Scripture that talk about some falling away. Sometimes I struggle with assurance because of the sin that I struggle with and the circumstances I find myself in. I know my salvation is not contingent on my ability to obey, or anything that has to do with me, but rather Christ’s perfect obedience and work on the cross. I just constantly worry whether my faith and repentance is genuine and that I am not just filling myself up with more head knowledge of God. I am really struggling to know if my faith is either very weak or non-existent. How does one practically look to Christ when they feel as if they are hated by Him because of things they have done?

    • Makda,

      Rest easy my brother.

      You are doing what Christians often do, looking upon the quality of your faith rather than looking upon the quality of your Savior. You and I have a great Savior, who loves to save helpless sinners such as us. He does it and no one can snatch us from his hand.

      Yes, our faith waivers and totters but that is because we are sinners. Jesus is not a sinner and thus he never wavers in his love for and faithfulness to us.

      How can I be so bold? Because unbelievers do not worry about their assurance. Nervous believers, who’ve been looking at themselves and their sins worry.

      What matters is not the quality of your faith, whether it possesses enough of this quality or that but whether it is. The smallest faith lays hold of the greatest Savior!

      Trust his promises. He will not let you down.

      This might encourage you:

      Can I Have Assurance?

      • Thank you for that encouragement Dr. Clark! I just have a tendency to be really scrupulous and introspective at times instead of just laying hold of what Christ has done for sinners. When looking at the evidences of my short life as a believer thus far, it makes me really anxious and most times despondent. I guess I have to learn to look to Christ again and again with childlike faith despite my feeble efforts and continued failures.

  3. “How can I be so bold? Because unbelievers do not worry about their assurance. Nervous believers, who’ve been looking at themselves and their sins worry.”

    Thank you for this. I often struggle with assurance. As a recent convert to the confessional reformed faith, practice and piety found in the Three Forms of Unity from a pietistic baptist background (still learning), this is a breath of fresh air, water in the desert. Far too often I am looking at my own faith and repentance and wondering whether or not my faith is strong enough or whether or not I have enough godly sorrow for my sins. I must learn to repent of my perfectionist expectations.

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