St. Matthew the 18^th chapter, verses 1-5

At that time the disciples came to Jesus and asked, “Who, then, is the greatest in the kingdom of heaven?”² He called a little child to him, and placed the child among them. ³ And he said: “Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven. ⁴ Therefore, whoever takes the lowly position of this child is the greatest in the kingdom of heaven. ⁵ And whoever welcomes one such child in my name welcomes me.