Being "born again" is something that only God can do in our lives. The Lord Jesus once told a religious teacher that while flesh can only give birth to flesh, only the Spirit can give birth to spirit (see John 3:6). And just like how a person's birth is evidenced by his physical body along with a heartbeat and loud cries, a person who got born again will also show some proof of it.
The Need for Evidence
I've once heard a preacher comically point out that many try to emphasise the exact date when they met the Lord Jesus Christ, but fail to show signs of it. This preacher noted that while he does not remember what happened during his physical birth, he knows that he was born because he is alive. In the same way, he knows he got born again because there's proof of him being saved by Jesus.
Knowing this, we should also check ourselves if we've really borne fruit from the salvation that we have received in Christ Jesus. Yes, we might not see where the Spirit comes from or where He goes to just like the wind, but we do know that He came blowing towards us when we met Christ (see John 3:8).
Do you want to know if you're truly born again? Here are some pieces of evidence that the Spirit is producing life in you and that you are responding to Christ.
1. Repentance From Sin
The first thing that happens when we are born again is that we realise how sinful we are, and we'd want to repent of our sins, turning away from all of them. Those who come face to face with Christ and behold His holiness will have a response like Isaiah's:
"And I said: 'Woe is me! For I am undone because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips. For my eyes have seen the King, the Lord of Hosts.'" (Isaiah 6:5)
2. A Desire to Live a Righteous Life in Christ — Leaving Behind the Old, Sinful Life
Those who encounter Christ and repent of their sins will want to do what is right from that point on. For some, it will mean making things right, like how it meant to Zacchaeus:
"But Zacchaeus stood and said to the Lord, 'Look, Lord, I give half of my possessions to the poor. And if I have taken anything from anyone by false accusation, I will repay him four times as much.'" (Luke 19:8)
3. A Mouth That Can't Stop Speaking the Truth of Christ's Gospel Always – Even If Opposed
Those who have truly been born again cannot stop but speak of God's goodness in Christ even if they face opposition and ridicule. After all, their lives don't matter to them anymore because Christ is now their life.
"But Peter and John answered them, 'Whether it is right in the sight of God to listen to you more than to God, you judge. For we cannot help but declare what we have seen and heard.'"(Acts 4:19-20)