By essence, it is his origin that determines man. It is this that decides how much understanding he has of himself, of his being, of his opinions, of his behavior. Born of the flesh, we can only understand ourselves according to the world. But being born of the Spirit allows us to have a new perception of ourselves.The old man does not simply become better by being reborn, he acquires a new origin. The rebirth is indispensable, Jesus says that it must happen. Through this revelation, God answers the question of man in view of salvation, because man can not give himself an answer. But one can not simply say that man becomes "better" by being born again; his life acquires meaning.
TThis looks like the wind; it can not be disposed of at will. You can not grasp it, because it blows where it wants. Something must be manifested in the life of the one born of the Spirit: his thoughts and actions can not be understood according to the criteria of the world. The good that he does does not come from himself.