Who is the greatest in the kingdom of heaven?

The disciples came to Jesus and asked, "Who is the greatest in the kingdom of heaven?" He called a child, whom he put among them, and said,

"Truly I tell you, unless you change and become like children, you will never enter the kingdom of heaven. Whoever becomes humble like this child is the greatest in the kingdom of heaven. Whoever welcomes one such child in my name welcomes me.