Conversion in the New Testament

Conversion can be defined as turning away from sin and turning to God. A classic verse that reflects this definition is 1 Thessalonians 1:9: «For they themselves report about us, what kind of entrance we had among you, and how you turned to God from idols to serve the living and true God.» Here, two elements of conversion are clearly seen: turning to God and turning from idols.

Conversion in the New Testament: From Promise to Reality

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 in the life, death, and resurrection of Jesus Christ, which are proclaimed in the New Testament, we see the beginning of the fulfillment of all these promises.

Conversion in the Synoptic Gospels

In the Synoptic Gospels (Matthew, Mark, and Luke), the saving work of God promised in the Old Testament is summarized by the term «the Kingdom of God.» This Kingdom plays a central role in the Synoptic texts, but it is also important to understand that the Kingdom requires conversion.

The two elements of conversion can also be described in terms of repentance and faith. As we read in Mark 1:14-15: «Now after John was put in prison, Jesus came into Galilee, preaching the gospel [of the kingdom 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 captivity, proclaimed by the prophet Isaiah, the good news of the fulfillment of God’s saving promises, will be a joy only for those who repent of their sins and believe in the gospel.

The Synoptic Gospels focus on the death and resurrection of Jesus, for the suffering and resurrection of Jesus dominate all three books. This is the climax of history! There is no Kingdom without the cross. Jesus came to «save his people from their sins» (Matt. 1:21), and this salvation is accomplished only through his death for them, in which he gave «his life a ransom for many» (Matt. 20:28; cf. Mark 10:45). Some who speak of the Kingdom make little mention of conversion, but even a cursory glance at the Synoptic Gospels shows that conversion is fundamental. No one can enter the Kingdom without it (cf. Mark 10:17-31).

Conversion in the Gospel of John

The centrality of conversion is also evident 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 his Gospel, emphasizing the importance of this theme. Faith in John is not passive. He uses many terms to convey the depth and activity of faith: to believe is like eating, drinking, seeing, hearing, dwelling, coming, entering, receiving, and obeying. The radical nature of conversion is expressed through the variety of verbs that John uses to describe what it means to believe that Jesus is the Christ.

Conversion, then, is at the heart of the message of John’s Gospel. Eternal life (life in the next age) belongs only to 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 the Acts of the Holy Apostles

From the above, it is clear that conversion plays a central role in the Gospels, and we can draw the same conclusion from the book of Acts of the Apostles. In Acts we find a number of sermons in which the Gospel is explained to the listeners (e.g., Acts 2:14-41; 3:11-26; 13:16-41). The listeners are often called to repentance (Acts 2:38; 3:19; 8:22; 17:30; 26:20), which is also defined as «conversion» to God (Acts 3:19; 9:35, 40; 11:21; 14:15; 15:19; 26:18, 20; 28:27). The Gospel message contains an urgent call to turn away from sin and the old life. At the same time, those who hear the Good News are called to believe and act in faith (Acts 16:31; 26:18). Indeed, the word “believers” is used nearly 30 times in Acts to describe Christians.

It is not surprising that conversion plays an important role in this book, since it describes the spread of the gospel from Jerusalem to Rome (Acts 1:8). But it should also be noted that the kingdom of God is the main theme in the Acts of the Apostles. It frames the book at the beginning (Acts 1:3) and at the end (Acts 28:31). Paul preached the kingdom in Rome (Acts 20:35; 28:23, 31), and Philip «preached the good news of the kingdom of God and the name of Jesus Christ» (Acts 8:12), demonstrating that the kingdom is centered on the gospel. Thus we have further evidence that conversion is the basis for any proclamation of the kingdom. The restoration of the world under God’s rule is the glorious hope of believers, but only those who have repented and believed will be able to enjoy the new world to come. Those who refuse to believe will be judged.

Conversion to Paul

Paul does not often use the term «Kingdom of God,» but his eschatological worldview is well known and is consistent with the eschatological character of the Kingdom. Like the Gospels, he proclaims an eschatology that has already come, but is not yet fully realized. Most scholars agree that faith and repentance are key themes in Paul’s epistles. Paul often teaches that justification and salvation are obtained through faith alone (cf. Rom. 3:21-4:25; Eph. 2:8-9; Phil. 3:2-11). He does not use the word «repentance» as often, but it is not entirely absent (e.g. Rom. 2:4; 2 Tim. 2:25). Certainly, the saving work of God in Christ plays an important role in his theology, but such salvation is granted only to those who believe, that is, 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), and only those who have repented will belong to the new creation that is coming. Therefore, Paul works intensively to spread the Gospel among the Gentiles (Col. 1:24-2:5), seeking to bring the Gospel to those who have never heard it (Rom. 15:22-29) so that they may be included in the circle of the saved.

Conversion in other epistles

The remaining letters of the New Testament are episodic messages addressed to specific situations. However, the importance of conversion is either specifically stated or implied in them.

For example, the Book of Hebrews states that only those who believe and obey will enter into rest in the last days (Heb. 3:18, 19; 4:3; 11:1-40).

The Epistle of James is often misinterpreted, but when interpreted correctly, it can be argued that faith accompanied by repentance is necessary for justification (James 2:14-26).

Likewise, the Apostle Peter teaches that salvation is the result of faith (1 Pet. 1:5; 2 Pet. 1:1), and 1 John is written to assure those who believe that they have eternal life (1 John 5:13).

Conversion in Revelation

The book of Revelation concludes this story by assuring believers that the Kingdom of God, which has already come in Jesus Christ, will be consummated. Those who do evil and compromise with the Beast will be condemned forever, but those who endure to the end will enter the heavenly city, the new Jerusalem. Revelation emphasizes that only those who repent (Rev. 2:5, 16, 21, 22; 3:3, 19; 9:20, 21; 16:9, 11) will find life.

Not a central theme, but fundamental to the entire story

In conclusion, it can be argued that conversion is certainly not the central theme of Scripture. Believers were saved to glorify God and enjoy Him forever, and we can do so both in this world and in the world to come.

Conversion remains a key and indispensable element in the entire history of salvation, for only those who have experienced it will be able to enter into the joy of the new creation. People must turn from sin and turn to God in order to receive salvation. This involves repentance for their sins and faith in the Gospel of Jesus Christ, crucified and resurrected. On the day of the final judgment, it will not matter how many good works have been done to improve the world (however beneficial they may be) if a person has not converted to Christ.