Matthew 18:3

18:3 and said, “I tell you the truth, unless you turn around and become like little children, you will never enter the kingdom of heaven!

Luke 18:17

18:17 I tell you the truth, whoever does not receive the kingdom of God like a child will never enter it.”

John 3:3-6

3:3 Jesus replied, “I tell you the solemn truth, unless a person is born from above, he cannot see the kingdom of God.” 3:4 Nicodemus said to him, “How can a man be born when he is old? He cannot enter his mother’s womb and be born a second time, can he?”

3:5 Jesus answered, “I tell you the solemn truth, unless a person is born of water and spirit, he cannot enter the kingdom of God. 3:6 What is born of the flesh is flesh, and what is born of the Spirit is spirit.