What is judgement all about?

Therefore whoever humbles himself as this little child is the greatest in the kingdom of heaven. Whoever receives one little child like this 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 if a millstone were hung around his neck, and he were drowned in the depth of the sea. Woe to the world because of offenses! For offenses must come, but woe to that man by whom the offense comes! Matthew 18.4-7