This is the summary of John 3.
The first operation of God’s life: regeneration
The nine cases in the Gospel of John signify all human conditions. And this book shows how the life operates in each of the cases. The first operation in chapter 3 is regeneration: being reborn by water and the Spirit. Don’t think that this regeneration is needed for evil or weak people. See to whom the Lord talked about this matter of regeneration. It’s Nicodemus, a moral, good, humble, honest, high-class, intelligent, religious, God-seeking person. Even this good person needed to be regenerated.
The kingdom of God
Regeneration is a matter of life. To enter the kingdom of God is to participate in the kingdom and to be a member of the kingdom of God. For this we need to be regenerated, that is, to receive God’s life. The new life is the key to God’s kingdom. Think about the human kingdom and animal kingdom. They may live together at the same place, but they can’t be a member of each other’s kingdom because they have different kinds of life.
Life vs. knowledge
The opposite of life is knowledge. I don’t need to teach my dog how to bark, because he has the life of dog, and he already knows how to bark and he does bark himself. In the garden of Eden, what was the opposite of the tree of life? Was it a tree of death or evil? No, it was the tree of knowledge. Nicodemus was actually an essence of knowledge. He was a Pharisee, and he wanted teaching by calling Jesus a teacher. To Christians, what we need is not the knowledge of good and evil. We need life, God’s life, which has different nature from human life. Discipline is difficult. It may work, but it accompanies pain and it’s temporary. Once you get the new life, it doesn’t matter even if you do not know about the kingdom. The life will realize everything.
Brass serpent lifted up on the cross
Human beings are poisoned, no matter how good they look. When we behold Jesus on the cross, our poison goes away. This is equivalent to the principle of life, which is to change death into life. It is simple to receive the new life. Gaze upon the Lord, especially the Lord on the cross.