7 “Give heed unto me,” the Church says unto you; give heed unto me, whom you see, although to see ye be unwilling. For the faithful, who were in those times in the land of Judæa, were present at, and learned as present, Christ's wonderful birth of a virgin, and His passion, resurrection, ascension; all His divine words and deeds. These things you have not seen, and therefore ye refuse to believe. Therefore behold these things, fix your eyes on these things, these things which you see reflect on, which are not told you as things past, nor foretold you as things future, but are shown you as things present.
What? Seems it to you a vain or a light thing. and think you it to be none, or a little, divine miracle, that in the name of One Crucified the whole human race runs? You saw not what was foretold and fulfilled concerning the human birth of Christ, “Behold, a Virgin shall conceive in the womb, and shall bear a Son;” but you see the Word of God which was foretold and fulfilled unto Abraham, “In your seed shall all nations be blessed.” You saw not what was foretold concerning the wonderful works of Christ, “Come ye, and see the works of the Lord, what wonders He has set upon the earth:” but you see that which was foretold, “The Lord said unto Me, My Son are You, I have this day begotten You; demand of Me and I will give You nations as Your inheritance, and as Your possession the bounds of the earth.” You saw not that which was foretold and fulfilled concerning the Passion of Christ, “They pierced My hands and My feet, they numbered all My bones; but they themselves regarded and beheld Me; they divided among them My garments, and upon My vesture they cast the lot;” but you see that which was in the same Psalm foretold, and now is clearly fulfilled; “All the ends of the earth shall remember and be turned unto the Lord, and all the kindreds of the nations shall worship in His sight; for the kingdom is the Lord's, and He shall rule over the nations.” You saw not what was foretold and fulfilled concerning the Resurrection of Christ, the Psalm speaking, in His Person, first concerning His betrayer and persecutors: “They went forth out of doors, and spoke together: against Me whispered all My enemies, against Me thought they evil for Me;” they set in order an unrighteous word against Me. Where, to show that they availed nothing by slaying Him Who was about to rise again, He adds and says; “What? Will not He, that sleeps, add this, that He rise again?” And a little after, when He had foretold, by means of the same prophecy, concerning His betrayer himself, that which is written in the Gospel also, “He that did eat of My bread, enlarged his heel upon Me,” that is, trampled Me under foot: He straightway added, “But do Thou, O Lord, have mercy upon Me, and raise me up again, and I shall repay them.” This was fulfilled, Christ slept and awoke, that is, rose again: Who through the same prophecy in another Psalm says, “I slept and took my rest; and I rose again, for the Lord will uphold Me.” But this ye saw not, but you see His Church, concerning whom it is written in like manner, and fulfilled, “O Lord My God, the nations shall come unto You from the extremity of the earth and shall say, Truly our fathers worshipped lying images, and there is not in them any profit.” This certainly, whether you want to or not, you behold; even although ye yet believe, that there either is, or was, in those idols some profit; yet certainly unnumbered peoples of the nations, after having left, or cast away, or broken in pieces such like vanities, you have heard say, “Truly our fathers worshipped lying images, and there is not in them any profit; shall a man make gods, and, lo, they are no gods?” Nor think that it was foretold that the nations should come unto some one place of God, in that it was said, “Unto You shall the nations come from the extremity of the earth.” Understand, if you can, that unto the God of the Christians, Who is the Supreme and True God, the peoples of the nations come, not by walking but by believing. For the same thing was by another prophet thus foretold, “The Lord,” says he, “shall prevail against them, and shall utterly destroy all the gods of the nations of the earth: and all the isles of the nations shall worship Him, each man from his place.” Whereas the one says, “Unto You all nations shall come;” this the other says, “They shall worship Him, each man from his place.” Therefore they shall come unto Him, not departing from their own place, because believing in Him they shall find Him in their hearts. You saw not what was foretold and fulfilled concerning the ascension of Christ; “Be exalted above the Heavens, O God;” but you see what follows immediately after, “And above all the earth Your Glory.” Those things concerning Christ already done and past, all of them you have not seen; but these things present in His Church ye deny not that you see. Both things we point out to you as foretold; but the fulfillment of both we are therefore unable to point out for you to see, because we cannot bring back into sight things past.
Source: Concerning Faith of Things Not Seen (New Advent)