Matthew 18:3-6

Most certainly I tell you, unless you turn and become as little children, you will in no way enter into the Kingdom of Heaven. Whoever therefore humbles himself as this little child is the greatest in the Kingdom of Heaven. Whoever receives one such little child in my name receives me, but whoever causes one of these little ones who believe in me to stumble, it would be better for him if a huge millstone were hung around his neck and that he were sunk in the depths of the sea.