Matthew 18: 1 - 5, 10
1 At that time the disciples came to Jesus, saying, "Who is the greatest in the kingdom of heaven?"
2 And calling to him a child, he put him in the midst of them,
3 and said, "Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven.
4 Whoever humbles himself like this child, he is the greatest in the kingdom of heaven.
5 "Whoever receives one such child in my name receives me;
10 "See that you do not despise one of these little ones; for I tell you that in heaven their angels always behold the face of my Father who is in heaven.

EWTN