Isaiah 65:18

Instead of the former affliction, the prophet says, "they shall find in her joy and exultation." To what does "in her" refer? Without a doubt it can be said that it refers to the church of Christ. It must be noted that some commentators refer this passage not to the period of our earthly life but to the one that is to come after this present age. For the prophet says that the just will find joy and gladness and will enjoy endless delight, that is, spiritual delight, when this creation had been transformed and renewed. For one of the holy apostles said: "The day of the Lord will come like a thief, and then the heavens will pass away with a loud noise, and the elements will be dissolved with fire, and the earth and the works that are upon it will be burned up. But according to his promise we wait for new heaven and a new earth." Choose, therefore, whichever of these interpretations appeals to you, the former or the latter. For one should not reject what brings benefit to us.

For it will not be fitting that in the city of Jerusalem, the people of God, who will receive the eternal creature of exultation and joy, should any longer hear the voice of weeping and shouting; when pain, sorrow, and groaning have departed. For indeed, opposites cannot be present at the same time. And where there is exultation and joy, which are the fruits of the Holy Spirit, there can be no weeping and lamentation, which are suitable for those who lament and mourn, especially the shouting, which Paul expels from the Church of believers, so that we do not make a clamor resembling that of the Jews (Ephesians 4). In such a city, there will be no diverse ages: infant and old, small and great, who do not fulfill their days; but like children of the resurrection, all will reach perfect adulthood, to the measure of the fullness of Christ's age, so that no one lacks the span of years, nor exceeds it, and one who does not yet have solid strength may cease to be what he was, and with advanced age may wither away; and all will reach the number of one hundred years, such as Abraham was, who received the promise of his son Isaac at this age (Gen. XXI). Of the praises of which number, it is not necessary to mention many, lest the discussion be superfluous. We only say this, that the tens have equal sides and possess the firmness of square shapes.