1 Further, also, concerning Jerusalem and the Lord, they venture to assert that, if it had been “the city of the great King,” it would not have been deserted. This is just as if any one should say, that if straw were a creation of God, it would never part company with the wheat; and that the vine twigs, if made by God, never would be lopped away and deprived of the clusters. But as these [vine twigs] have not been originally made for their own sake, but for that of the fruit growing upon them, which having come to maturity and been taken away, they are left behind, and those which do not conduce to fructification are lopped off altogether; so also [was it with] Jerusalem, which had in herself borne the yoke of bondage (under which man was reduced, who in former times was not subject to God when death was reigning, and being subdued, became a fit subject for liberty), when the fruit of liberty had come, and reached maturity, and been reaped and stored in the barn, and when those which had the power to produce fruit had been carried away from her [i.e., from Jerusalem], and scattered throughout all the world. Even as Esaias says, “The children of Jacob shall strike root, and Israel shall flourish, and the whole world shall be filled with his fruit.” The fruit, therefore, having been sown throughout all the world, she (Jerusalem) was deservedly forsaken, and those things which had formerly brought forth fruit abundantly were taken away; for from these, according to the flesh, were Christ and the apostles enabled to bring forth fruit. But now these are no longer useful for bringing forth fruit. For all things which have a beginning in time must of course have an end in time also.
2. Since, then, the law originated with Moses, it terminated with John as a necessary consequence. Christ had come to fulfil it: wherefore “the law and the prophets were” with them “until John.” And therefore Jerusalem, taking its commencement from David, and fulfilling its own times, must have an end of legislation when the new covenant was revealed. For God does all things by measure and in order; nothing is unmeasured with Him, because nothing is out of order. Well spoke he, who said that the unmeasurable Father was Himself subjected to measure in the Son; for the Son is the measure of the Father, since He also comprehends Him. But that the administration of them (the Jews) was temporary, Esaias says: “And the daughter of Zion shall be left as a cottage in a vineyard, and as a lodge in a garden of cucumbers.” And when shall these things be left behind? Is it not when the fruit shall be taken away, and the leaves alone shall be left, which now have no power of producing fruit?
3. But why do we speak of Jerusalem, since, indeed, the fashion of the whole world must also pass away, when the time of its disappearance has come, in order that the fruit indeed may be gathered into the garner, but the chaff, left behind, may be consumed by fire? “For the day of the Lord comes as a burning furnace, and all sinners shall be stubble, they who do evil things, and the day shall burn them up.” Now, who this Lord is that brings such a day about, John the Baptist points out, when he says of Christ, “He shall baptize you with the Holy Ghost and with fire, having His fan in His hand to cleanse His floor; and He will gather His fruit into the garner, but the chaff He will burn up with unquenchable fire.” For He who makes the chaff and He who makes the wheat are not different persons, but one and the same, who judges them, that is, separates them. But the wheat and the chaff, being inanimate and irrational, have been made such by nature. But man, being endowed with reason, and in this respect like to God, having been made free in his will, and with power over himself, is himself the cause to himself, that sometimes he becomes wheat, and sometimes chaff. Wherefore also he shall be justly condemned, because, having been created a rational being, he lost the true rationality, and living irrationally, opposed the righteousness of God, giving himself over to every earthly spirit, and serving all lusts; as says the prophet, “Man, being in honour, did not understand: he was assimilated to senseless beasts, and made like to them.”
Source: Adversus haereses (New Advent)