John 3:3-5

3 "Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God."
4 "Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?"
5 "Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God."