Thomas Aquinas, Compendium of Theology

We are not to suppose that judicial examination will be required in order that the judge may receive information, as is the case in human courts; for "all things are naked and open to His eyes," as we are told in Hebrews 4:13. The examination is necessary for the purpose of making known to each person, concerning himself and others, the reasons why each is worthy of punishment or of glory, so that the good may joyfully acknowledge God's justice in all things and the wicked may be roused to anger against themselves.

Nor should we imagine that this examination is to be conducted by oral discussion. Endless time would be required to recount the thoughts, words, and deeds, good or evil, of each person. Therefore Lactantius was deceived when he suggested that the day of judgment would last a thousand years. Even this time would scarcely be enough, as several days would be required to complete the judicial process for a single man in the manner proposed. Accordingly the divine power will bring it about that in an instant everyone will be apprised of all the good or evil he has ever done, for which he is to be rewarded or punished. And all this will be made known to each person, not only about himself, but also about the rest. Hence, wherever the good is so much in excess that the evil seems to be of no consequence or vice versa, there will seem, to human estimation, to be no conflict between the good and the evil. This is what we meant when we said that such persons will be rewarded or punished without examination.

Although all men will appear before Christ at that judgment, the good will not only be set apart from the wicked by reason of meritorious cause, but will be separated from them in locality. The wicked, who have withdrawn from Christ in their love of earthly things, will remain on earth; but the good, who have clung to Christ, will be raised up into the air when they go to meet Christ, that they may be made like Christ, not only by being conformed to the splendor of His glory, but by being associated with Him in the place He occupies. This is indicated in Matthew 24:28: "Wheresoever the body shall be, there shall the eagles also (by which the saints are signified) be gathered together." According to Jerome, instead of "body" the Hebrew has the significant word "joatham," which means corpse, to commemorate Christ's passion, whereby Christ merited the power to judge, and men who have been conformed to His passion are admitted into the company of His glory, as we are told by the Apostle in II Timothy 2:12: "If we suffer, we shall also reign with Him."

This is the ground for our belief that Christ will come down to judge somewhere near the place of His passion, as is intimated in Joel 3:2: "I will gather together all nations and will bring them down into the valley of Josaphat; and I will plead with them there." This valley lies at the foot of Mount Olivet, from which Christ ascended into heaven. For the same reason, when Christ comes for the judgment, the sign of the cross and other signs of the Passion will be displayed, as is said in Matthew 24:30: "And then shall appear the sign of the Son of man in heaven," so that the wicked, looking upon Him whom they have pierced, will be distressed and tormented, and those who have been redeemed will exult in the glory of their Redeemer. And as Christ is said to sit at God's right hand according to His human nature, inasmuch as He has been lifted up to share in the most excellent goods of the Father, so at the judgment the just are said to stand at Christ's right, as being entitled to the most honorable place near Him.