We tend to look at the lives of people who profess to be born again, and use them to define the word born again. Rather we should look at what scripture says concerning the born again believer, and use that as the standard.
The bible gives us a way to identify the new birth.
1. The born again Spirit can not sin
What is born of God in a man is his spirit and not his flesh.
John 3:6 (BBE)
That which has birth from the flesh is flesh, and that which has birth from the Spirit is spirit.
2 Corinthians 4:16
(WEB) Therefore we don’t faint, but though our outward man is decaying, yet our inward man is renewed day by day.
This born again spirit , also called the inner man can not sin. He has the nature of God just as Christ had the nature of God. So it is impossible for him to sin.
1 John 3:9
Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God.
Because your born again spirit can not sin, it is therefore impossible for those who are born again, though in the flesh to make a practice of sin. Because we are still in the flesh, we will occasionally give in to the flesh, and in those instances we confess to God.
1 John 5:18 New International Version (NIV)
18 We know that anyone born of God does not continue to sin; the One who was born of God keeps them safe, and the evil one cannot harm them.
2. The born again man listens to the doctrine of the apostles
Those who are born again will naturally connect with the words of the apostles because they are of the same spirit. Those who speak worldly things have the spirit of the world.
1 John 4:5-6 New International Version (NIV)
5 They are from the world and therefore speak from the viewpoint of the world, and the world listens to them. 6 We are from God, and whoever knows God listens to us; but whoever is not from God does not listen to us. This is how we recognize the Spirit of truth and the spirit of falsehood
3. The born again spirit will love God and Jesus
1 John 4:7 New King James Version (NKJV)
7 Beloved, let us love one another, for love is of God; and everyone who loves is born of God and knows God.
Just as we concluded on the issue of justification by faith. You do not do many good works inorder to get faith. If you exercise complete faith in God, good works will naturally flow.
Love is a fruit of the Spirit. If you are born again, Love will come naturally as a fruit from the Holy Spirit in you.
4. The born again man will believe that Jesus is the Christ
1 John 5:1 New International Version (NIV)
5 Everyone who believes that Jesus is the Christ is born of God, and everyone who loves the father loves his child as well.
5. The born again man will follow the commandments of Christ and overcome the world
1 John 5:2-4 New King James Version (NKJV)
2 By this we know that we love the children of God, when we love God and keep His commandments.
3 For this is the love of God, that we keep His commandments. And His commandments are not burdensome.
4 For whatever is born of God overcomes the world. And this is the victory that has overcome the world—our faith