Jesus answered him, reading his heart and knowing what he had come to ask, but taking the conversation in an entirely new unexpected direction. He did not answer him and give an answer which had nothing to do with the intentions of Nicodemus.
Of course it is. To relate to God, to belong to him, you need to have a capacity to have fellowship with him, to pray to him, to love him, to see things his way, to long for him, to desire him. You have got to be profoundly changed for all these things to take place within you. We cannot even see the kingdom of God without this.