The Baltimore Catechism: Question 104

104. What do we mean when we say that Christ will come from thence to judge the living and the dead?

When we say that Christ will come from thence to judge the living and the dead, we mean that on the last day Our Lord will come to pronounce a sentence of eternal reward or of eternal punishment on everyone who has ever lived in this world.

For the Son of Man is to come with his angels in the glory of his Father, and then he will render to everyone according to his conduct. (Matthew 16:27)