Wayne Grudem in his systematic theology, defines regeneration as "a secret act of God in which He imparts new spiritual life in us." Regeneration is more commonly referred to in the Bible as being born again. Being born again is an absolute necessity for salvation. " Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God." John 3:3. This is so because when we are born physically, we are born spiritually dead. As Paul said we "were dead in the trespasses and sins in which you once walked" and we "were by nature children of wrath." Ephesians 2:1,2,3. After Adam sinned we all died spiritually. So it doesn't matter who you are or where we live, we all need to be born again. You could be a great moral person with a religious pedigree all the way to John Calvin or you could be the most debased sinner but you still need to be born again.
Regeneration is something we play no part in. There are no commands in the Bible that we need to regenerate ourselves. Being born again is solely an act of God. Jesus referred to regeneration as being born of the Spirit."Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God." John 3:5. See also John 1:13 and 1 John 2:29. In fact while regeneration is primarily the work of the Holy Spirit, a close study of scripture reveals that all members of the Trinity are involved in regeneration. Just as we had no part to play when we were born the first time, so we play no part in being born the second time.
The word of God is what God uses to bring about the new life in Christ. "Since you have been born again not of perishable seed, but of imperishable, through the living and abiding word of God." 1 Peter 1:23. This is also confirmed by James in James 1:18, "Of His own will He brought us forth by the word of truth, that we should be a kind of first fruits of His creatures." In both these passages we learn that God uses His word, especially the gospel message, to bring about the new birth. This should make us see how important it is to communicate God's truth with accuracy in teaching and evangelism. Since God uses His word for regeneration, we should, in our evangelism, use scripture in our conversation and gospel literature.
There is a mystery in how this work of regeneration occurs in the heart of a person. "The wind blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit." John 3:8. How exactly God works as He transforms a person spiritually is unknown. For some people, they will know the precise day and moment of being born again and others may not realize all that is taking place inside them. But yet there is always a moment when God takes the old heart out and gives that person a new heart. We may not perceive it until later. While we may not know how God imparts new life in the hearts of people, we will always see the results.
The result of the work of regeneration will always be repentance, faith, justification, and sanctification. When God gives new life in the soul, the person will now see the holiness of God, the sinfulness of sin, and the beauty of Christ and the gospel. He will respond to his sins with godly sorrow and true repentance. He will lean on the finished work of Christ for his complete salvation. When he does that, then God declares that person not guilty and righteous based on the sacrifice and righteousness of Jesus Christ. The Christian is now a new creature in Christ and as such he will live differently. There will be increasing conformity to the character of Christ in a Christian's life.
John's first letter gives some of the signs of a person who has been born of God.
1) One who is born again will not continue to live in sin. There will be true repentance and forsaking of sin. He will hate sin not love it. 1 John 3:9 and 1 John 5:18
2) The one who is born again will trust that Jesus is the only Saviour for sinners. 1 John 5:1
3) The regenerated person will desire and try to live a godly life. 1 John 2:29
4) One who is born again will love God's people, His church. 1 John 3:14
5) One truly born again will not love worldliness. 1 John 5:4
Are these signs in your life? This is an important question, for there is no other way to enter heaven. Let me finish with an illustration that I have modified from Charles Spurgeon. Suppose there was a rule in Canada that only those who were born in Canada could become citizens of this country. Now a man from Japan comes to Canada and wishes to be a Canadian citizen. He is told that is impossible. So he says that he will dress like a Canadian and eat Canadian food. Will that help him to become a citizen? No, but this man truly is willing to become a citizen so he says that he will also learn English and just to show his sincerity he will learn French too. We would admire his zeal, but the law is the law. But he continues on, "I will change my name so it is a Canadian name like Wayne or Pierre. I will study the customs and traditions of this country so that I will be able to be a typical Canadian." Sadly this man still would not be allowed to be a citizen. So it is with the heavenly country. In order to become a citizen of God's country, you must be born again. No amount of outward good deeds can get you in. Only by God's sovereign grace can you become a citizen of that country. While we cannot regenerate ourselves, God does call all of us to repent and believe in Christ.