“It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life.” … So Jesus said to the Twelve, “Do you want to go away as well?” Simon Peter answered him, “Lord, to whom shall we go? You have the words of eternal life, and we have believed, and have come to know, that you are the Holy One of God.”
People are being born again through the work of Spirit who works through the word of God. By conversation with Jesus and hearing what he says, people were born again. God works the same way in the present too. Jesus has the words of eternal life. What he says is spirit and life.