Because sin is not merely doing bad things but an even deeper problem of building our identity on someone or something other than God alone, the solution to idolatry is not to change our behavior but to have a complete reorientation of our nature at the deepest level of our being, or what Jesus called being born again.

You must be born again

In the third chapter of John’s Gospel, a man named Nicodemus came to meet with Jesus. Nicodemus was a devoutly religious man. As a Pharisee, he would have committed large sections of the Hebrew Old Testament to memory and been revered as morally upright, intelligent, and among the holiest of men. In John 3:3, Jesus said to him, “Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God.” This confused Nicodemus, so Jesus explained that there are two births. The first birth is our physical birth that occurs when our mother’s water breaks and we are brought into this world. By virtue of our first birth we are physically alive but spiritually dead. The second birth is our spiritual birth whereby God the Holy Spirit causes us to be born again so that we are both physically and spiritually alive.

Unlike religion, which is based on fear that forces people to do what they do not want to do, regeneration is based on love and God inviting new people to live new lives of worship.

Nicodemus considered himself spiritually alive by virtue of his religion, spirituality, theology, and morality. But he was likely astounded when Jesus told him plainly, “You must be born again” (John 3:7).

We need life, not religion

In this way he was much like those today who know some theological truth, have been baptized, attend religious meetings, live a “moral” life, believe in God, devote time to serve others, and even give some of their income to spiritual causes and organizations as members, leaders, and pastors who need to be born again. Why? Because they are living out of their old nature solely by their will and effort rather than out of a new nature by the power of God the Holy Spirit. John Piper says in his book, Finally Alive: What Happens When We Are Born Again:

What Nicodemus needs, and what you and I need, is not religion but life. The point of referring to new birth is that birth brings a new life into the world. In one sense, of course, Nicodemus is alive. He is breathing, thinking, feeling, acting. He is a human created in God’s image. But evidently, Jesus thinks he’s dead. There is no spiritual life in Nicodemus. Spiritually, he is unborn. He needs life, not more religious activities or more religious zeal. He has plenty of that.

Regeneration is being born again

Being born again is theologically summarized as the doctrine of regeneration, which is the biblical teaching that salvation includes both God’s work for us at the cross of Jesus and in us by the Holy Spirit. To say it another way, regeneration is not a separate work of the Holy Spirit added to the saving work of Jesus; rather, it is the subjective actualization of Jesus’ work.

While the word “regeneration” only appears twice in the Bible (Matthew 19:28, Titus 3:5), it is described in both the Old and New Testaments by a constellation of images. It is important to note that each signifies a permanent, unalterable change in someone at his or her deepest level.

The imagery of regeneration in Scripture

The Old Testament frequently speaks of regeneration in terms of deep work in the heart, our total inner self, so that a new life flows from a new heart empowered by the Holy Spirit, just as Jesus explained to Nicodemus (Deuteronomy 30:6; Jeremiah 24:7; 31:31–33; 32:39–40; Ezekiel 11:19–20; 36:26–27).

Like the Old Testament, the New Testament speaks of being born again on many occasions (John 1:13; 1 Peter 1:3, 23; 1 John 5:1). Elsewhere in the New Testament, many other images are used to explain regeneration. These include “partakers of the divine nature," (2 Peter 1:4) “new creation,” (2 Corinthians 5:17) “new man,” (Ephesians 2:15; 4:24) “alive together with Christ,” (Ephesians 2:5; Colossians 2:13) and “created in Christ Jesus” (Ephesians 2:10).

New Testament truths about regeneration

1. Regeneration is done to ill-deserving, not just undeserving, sinners (Ephesians 2:1–5). Therefore, regeneration is a gift of grace, as Titus 3:5 says: “he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit.” 
2. Regeneration is something God the Holy Spirit does for us (John 3:5–8). Therefore, unless God accomplishes regeneration in a person, it is impossible for them to live as a worshiper of God. 
3. Without regeneration there is no possibility of eternal life in God’s kingdom (John 3:3, 5; cf. 1 Corinthians 2:6–16). Therefore, regeneration is required for someone to be a true worshiper of God.

What happens to a regenerated person?

Accompanying the new birth are ten soul-transforming, life-changing, and eternity-altering occurrences (For further reading, see Question 4 of Religion Saves: And Nine Other Misconceptions).

1. A regenerated person has the Trinitarian Creator God of the Bible as their new Lord, thereby displacing all other false and functional lords who had previously ruled over them (1 John 5:18).
2. A regenerated person is a new creation so that they are transformed at the deepest levels of their existence to begin living a new life. People being renamed at their conversion, so that Saul becomes Paul and Cephas becomes Peter, illustrates that we are new people in Christ (2 Corinthians 5:17; Gal. 6:15).
3. A regenerated person has a new identity from which to live their new life because their old identity no longer defines them (Ephesians 4:22–24).
4. A regenerated person has a new mind that enables them to enjoy Scripture and thus to begin to think God’s truthful thoughts after him (Romans 7:22; 1 Corinthians 2:14–16; 1 Peter 2:2).
5. A regenerated person has new emotions so that they love God, fellow Christians, strangers, and even their enemies (1 John 4:7).
6. A regenerated person has new desires for holiness and no longer is their deepest appetite for sin and folly (Psalm 37:4; Romans 7:4-6; Galatians 5:16–17).
7. A regenerated person enjoys a new community and fellowship with other Christians as members of the church (1 John 1:3).
8. A regenerated person lives by a new power to follow God by the Holy Spirit’s enabling (Romans 8:4–13).
9. A regenerated person enjoys a new freedom to no longer tolerate, manage, excuse, or accept their sin but rather put it to death and live free from habitually besetting sin (Rom. 6:6; 7:6). 
10. The culmination of the effects of regeneration is a new life of worship that is markedly different from how life would otherwise be (Galatians 5:19–23).

New birth, new needs

In some ways our new birth is like our birth. Upon birth someone cries, moves, hungers, trusts their father to protect and provide for them, enjoys human comfort, and begins to grow. Similarly, a newly born-again person cries out to God in prayer, moves out in new life, hungers for the Scriptures, trusts God as their Father, enjoys God’s family the church, and begins to grow spiritually, maturing in their imaging of God.

G. K. Beale explains regeneration in terms of how Christians become restored into the image of God in his book, We Become What We Worship: A Biblical Theology of Idolatry:

It is in Christ that people, formerly conformed to the world’s image (Romans 1:18-32), begin to be transformed into God’s image (Romans 8:28-30; 12:2; 2 Corinthians 3:18; 4:4). . . . This process of transformation into the divine image will be completed at the end of history, when Christians will be resurrected and fully reflect God’s image in Christ (1 Corinthians 15:45-54; Philippians 3:20-21). They will be resurrected by the Spirit-imparting power of the risen Christ. Since it was the Spirit who raised Jesus from the dead (Romans 1:4), so the Spirit of Christ will raise Christians from the dead at the end of the age. . . . The Spirit’s work in people will enable them to be restored and revere the Lord and resemble his image, so that God will be glorified in and through them. 

Regeneration is an invitation to worship

Therefore, it is only through the regenerating and ongoing empowering ministry of the Holy Spirit that we can worship, until one day in our glorified resurrected state we image God perfectly as unceasing worshipers. This is exactly what Jesus meant when he said in John 4:24, “God is spirit, and those who worship him must worship in spirit and truth.” Commenting on this verse in his book John: Baker Exegetical Commentary on the New Testament, Andreas Köstenberger says:

The terms “spirit” and “truth” are joined later in the expression “Spirit of truth,” referring to the Holy Spirit (see 14:17; 15:26; 16:13; cf. 1 John 4:6; 5:6; see also 2 Thessalonians 2:13) . . . the present reference therefore seems to point John’s readers ultimately to worship in the Holy Spirit. Thus, true worship is not a matter of geographical location (worship in a church building), physical posture (kneeling or standing), or following a particular liturgy or external rituals (cf. Matthew 6:5–13); it is a matter of the heart and of the Spirit.”          

A regenerated heart shares the desires of God

Importantly, because of our new hearts, worshiping God by imaging him well through the empowerment of the Holy Spirit is exactly what we want to do in our innermost depths. Speaking of the Spirit-empowered regenerated desires of the heart Psalm 37:4 says, “Delight yourself in the Lord, and he will give you the desires of your heart.” Practically, this means that as we enjoy and delight in who God is, what he has done, and what he will do for us, our regenerated hearts share in the same desires of God. Subsequently, unlike religion, which is based on fear that forces people to do what they do not want to do, regeneration is based on love and God inviting new people to live new lives of worship, which is exactly what their new hearts want to do at the deepest level. The result is ever-growing, never-ending, ever-worshiping, passionate joy!

Adapted from Doctrine: What Christians Should Believe by Mark Driscoll and Gerry Breshears.