John 3:3-6 New American Standard Bible (NASB)
3 Jesus answered and said to him, “Truly, truly, I say to you, unless one is born [a]again he cannot see the kingdom of God.”
4 Nicodemus *said to Him, “How can a man be born when he is old? He cannot enter a second time into his mother’s womb and be born, can he?” 5 Jesus answered, “Truly, truly, I say to you, unless one is born of water and the Spirit he cannot enter into the kingdom of God. 6 That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.