Matthew 18:1-6 ESV
At that time the disciples came to Jesus, saying, “Who is the greatest in the kingdom of heaven?” And calling to him a child, he put him in the midst of them and said, “Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven. Whoever humbles himself like this child is the greatest in the kingdom of heaven.
“Whoever receives one such child in my name receives me, but whoever causes one of these little ones who believe in me to sin, it would be better for him to have a great millstone fastened around his neck and to be drowned in the depth of the sea.
ESV: English Standard Version 2016