This last we now see fulfilled; and thus this which cannot be denied establishes the truth of that which some have denied through ignorance, the last judgment namely, which He will hold upon earth, when He Himself shall come from heaven. For who could have expected that the Gentiles would have hope in Christ’s name, when He was in the hands of His enemies, when He was bound, scourged, set at nought, and crucified; when even His disciples had lost that hope which they had begun to have in Him! That which one thief hardly hoped on the cross, the nations scattered far and wide now hope. And that they may not die for ever, they are marked with that very cross on which He died. Let none then doubt that the last judgment will be by Christ Himself.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: City of God, book xx, ch. 30