Conversion in the New Testament


This is part 2 of a two part biblical theology of conversion. Click here for part 1.

Conversion may be defined as turning away from sin and turning to God. Perhaps the classic verse which captures this definition is 1 Thessalonians 1:9: “For they themselves report concerning us the kind of reception we had among you, and how you turned to God from idols to serve the living and true God.” Here we see clearly the two elements of conversion, turning to God and turning away from idols.


The story of God’s triumph over the serpent promised in the Old Testament (Gen. 3:15) becomes a reality in the New Testament. The Old Testament promised a new covenant, a new creation, a new exodus, and new hearts for God’s people. And there is an inaugurated fulfillment of all of these promises through the life, death, and resurrection of Jesus Christ, which is proclaimed in the New Testament.

Conversion in the Synoptics

In the synoptic Gospels (Matthew, Mark, and Luke), the saving work of God promised in the Old Testament is encapsulated by the term “kingdom of God.” The kingdom of God plays a central role in the Synoptics, but we must also understand that the kingdom calls for conversion. The two elements of conversion can also be described in terms of repentance and faith. As we read in Mark 1:14-15, “Jesus came into Galilee, proclaiming the gospel of God, and saying, ‘The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel’” (cf. Matt. 4:17). The good news of the return from exile heralded by Isaiah, the good news of the fulfillment of God’s saving promises, will be enjoyed only by those who repent of their sins and believe in the gospel.

The gospel in the synoptics centers on the death and resurrection of Jesus, for the passion and resurrection of Jesus dominate the story in all three books. It is the climax of the story! There is no kingdom without the cross. Jesus came to “save his people from their sins” (Matt. 1:21), and this salvation is realized only through his death on their behalf in which he gave “his life as a ransom for many” (Matt. 20:28; cf. Mark 10:45). Some who talk about the kingdom say little about conversion, but even a quick glance at the synoptic Gospels indicates that conversion is fundamental. One can’t enter the kingdom without it (cf. Mark 10:17-31).

Conversion in John

The centrality of conversion is also apparent in the Gospel of John. Indeed, John wrote his Gospel so that people would “believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name” (John 20:31). John uses the verb “believe” 98 times in the Gospel, underscoring the importance of this theme in his Gospel. Nor is believing in John passive. John uses a number of terms to convey the depth and activity of faith: believing is like eating, drinking, seeing, hearing, abiding, coming, entering, receiving, and obeying. The radical nature of conversion is expressed through the various verbs John uses to describe what it means to believe that Jesus is the Christ. Conversion, then, is at the very heart of the message of the Gospel of John. Eternal life (life in the age to come) belongs only those who believe in Jesus as “the Lamb of God, who takes away the sin of the world” (John 1:29). In other words, only those who are converted enjoy eternal life.

Conversion and the Kingdom in Acts

It seems clear from the above discussion that conversion plays a central role in the Gospels, and we can draw the same conclusion from the book of Acts. In Acts we find a number of sermons in which the gospel is explained to the hearers (e.g., Acts 2:14-41; 3:11-26; 13:16-41). Those hearing are often summoned to repent (Acts 2:38; 3:19; 8:22; 17:30; 26:20), which is also defined as “turning” to God (Acts 3:19; 9:35, 40; 11:21; 14:15; 15:19; 26:18, 20; 28:27). The gospel message involves an urgent call to turn away from sin and one’s old life. At the same time, those hearing the good news are summoned to believe and to exercise faith (Acts 16:31; 26:18). Indeed, the word “believing” is used nearly 30 times in Acts to describe Christians, indicating that faith characterizes those belonging to Christ.

It is scarcely surprising that conversion plays a major role in Acts since it records the spread of the gospel from Jerusalem to Rome (Acts 1:8; cf. also 1:6; 14:22). But it should also be observed that the kingdom of God is a major theme in Acts. It frames the book at the beginning (Acts 1:3) and end (Acts 28:31). Paul preached the kingdom in Rome (Acts 20:35; 28:23, 31), and Philip “preached the good news about the kingdom of God and the name of Jesus Christ” (Acts 8:12), demonstrating that the kingdom centers on the gospel. The gospel that was proclaimed called upon the hearers, as we saw above, to repent and believe. Hence, we have another piece of evidence that conversion is foundational to any proclamation of the kingdom. The restoration of the world to God’s rule is the glorious hope of believers, but only those who have repented and believed will enjoy the new world that is coming. Those who refuse to believe, as Acts emphasizes frequently, will be judged.

Conversion in Paul

Paul doesn’t use the term kingdom of God often, but his eschatological worldview is well-known, and it accords with the eschatological character of the kingdom. Like the Gospels, he proclaims an already/not yet eschatology. Most scholars would agree that faith and repentance are crucial themes in the Pauline epistles. Paul often teaches that justification and salvation are obtained only by faith (cf. Rom. 3:21-4:25; 9:30-10:17; 1 Cor. 15:1-4; Gal. 2:16-4:7; Eph. 2:8-9; Phil. 3:2-11). He doesn’t use the word repentance as often, but it is not completely absent (e.g., Rom. 2:4; 2 Cor. 3:16; 1 Thess. 1:9; 2 Tim. 2:25). Paul uses many terms for the saving work of God in Christ, including salvation, justification, redemption, reconciliation, adoption, propitiation, and so on. It is indisputable that the saving work of God in Christ plays a major role in Pauline theology, but such salvation is only granted to those who believe, to those who are converted.

According to Paul, believers eagerly await the return of Jesus Christ and the restoration of creation (Rom. 8:18-25; 1 Thess. 4:13-5:11; 2 Thess. 1:10), and yet only those who are converted will belong to the new creation that is coming. Hence, Paul labors intensely to spread the gospel to the Gentiles (Col. 1:24-2:5), striving to bring the gospel to those who have never heard (Rom. 15:22-29), so that they will be among the circle of those saved.

Conversion in the General Epistles

The remaining letters of the NT are occasional writings addressed to specific situations. Still, the importance of conversion is stated or implied. For instance, we find in Hebrews that only those who believe and obey will enter the end-time rest (Heb. 3:18, 19; 4:3; 11:1-40). James has often been misunderstood, but rightly interpreted he teaches that a repentant faith is necessary for justification (Jas. 2:14-26). So too, Peter teaches that salvation is by faith (1 Pet. 1:5; 2 Pet. 1:1), and 1 John was written to assure those who believe that they have eternal life (1 John 5:13).

Conversion in Revelation

The book of Revelation culminates the story, assuring believers that God’s kingdom, which has already come in Jesus Christ, will be consummated. Those who practice evil and compromise with the Beast will be judged forever, but those who persevere to the end will enter the heavenly city, which is the new Jerusalem. Revelation underscores that only those who repent (Rev. 2:5, 16, 21, 22; 3:3, 19; 9:20, 21; 16:9, 11) will find life.


To sum up, conversion is certainly not the central theme of Scripture. Believers were made to glorify God and to enjoy him forever, and we enjoy him and glorify him both in this world and in the world to come.

But conversion is foundational and fundamental to the story, since only those who are converted will enjoy the new creation. Human beings must turn from sin and turn to God to be saved. They must repent of their sins and believe in the gospel of Jesus Christ crucified and risen. It will be small consolation on the last day if one has contributed in a small way or even a significant way to the improvement of this world (as helpful as this is), if one is not converted.

This is part 2 of a two part biblical theology of conversion. Click here for part 1.

Thomas R. Schreiner

Thomas R. Schreiner is a Professor of New Testament Interpretation at The Southern Baptist Theological Seminary in Louisville, Kentucky, and the Pastor of Preaching at Clifton Baptist Church. You can find him on Twitter at @DrTomSchreiner.

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