For hence it is that it is said to Jeremiah when sent to preach, See, I have this day set thee over the nations and over the kingdoms, to pluck out, and to pull down, and to destroy, and to scatter, and to build, and to plant (Jer. i.10). Because, unless he first destroyed wrong things, he could not profitably build right things; unless he plucked out of the hearts of his hearers the thorns of vain love, he would certainly plant to no purpose the words of holy preaching. Hence it is that Peter first overthrows, that he may afterwards build up, when he in no wise admonished the Jews as to what they were now to do, but reproved them for what they had done, saying, Jesus of Nazareth, a man approved of God among you by powers and wonders and signs, which God did by Him in the midst of you, as ye yourselves know; Him, being delivered by the determinate counsel and foreknowledge of God, ye have by the hands of wicked men crucified and slain; whom God hath raised up, having loosed the pains of hell (Acts ii.22-24); in order, to wit, that having been thrown down by a recognition of their cruelty, they might hear the building up of holy preaching by so much the more profitably as they anxiously sought it. Whence also they forthwith replied, What then shall we do, men and brethren? And it is presently said to them, Repent and be baptized, every one of you (Ibid.37, 38). Which words of building up they would surely have despised, had they not first wholesomely become aware of the ruin of their throwing down. Hence it is that Saul, when the light from heaven shone upon him, did not hear immediately what he was to do aright, but what he had done wrong. For, when, fallen to the earth, he enquired, saying, Who art Thou, Lord? it was straightway replied, I am Jesus of Nazareth, whom thou persecutest. And when he forthwith replied, Lord, what wilt Thou have me to do? it is added at once, Arise, and go into the city, and it shall be told thee there what thou must do (Acts ix.4, &c.; xxii.8, &c.). Lo, the Lord, speaking from heaven, reproved the deeds of His persecutor, and yet did not at once shew him what he had to do. Lo, the whole fabric of his elation had already been thrown down and then, humble after his downfall, he sought to be built up: and when pride was thrown down, the words of building up were still kept back; to wit, that the cruel persecutor might long lie overthrown, and rise afterwards the more firmly built in good as he had fallen utterly upset from his former error. Those, then, who have not as yet begun to do any good are first to be overthrown by the hand of correction from the stiffness of their iniquity, that they may afterwards be lifted up to the state of well-doing. For this cause also we cut down the lofty timber of the forest, that we may raise it up in the roof of a building: but yet it is not placed in the fabric suddenly; in order, that is, that its vicious greenness may first be dried out: for the more the moisture thereof is exuded in the lowest, by so much the more solidly is it elevated to the topmost places.
But, on the other hand, those who in no wise complete the good things they have begun are to be admonished to consider with cautious circumspection how that, when they accomplish not their purposes, they tear up with them even the things that had been begun. For, if that which is seen to be a thing to be done advances not through assiduous application, even that which had been well done falls back. For the human soul in this world is, as it were, in the condition of a ship ascending against the stream of a river: it is never suffered to stay in one place, since it will float back to the nethermost parts unless it strive for the uppermost. If then the strong hand of the worker carry not on to perfection the good things begun, the very slackness in working fights against what has been wrought. For hence it is that it is said through Solomon, He that is feeble and slack in work is brother to him that wasteth his works (Prov. xviii.9). For in truth he who does not strenuously execute the good things he has begun imitates in the slackness of his negligence the hand of the destroyer. Hence it is said by the Angel to the Church of Sardis, Be watchful, and strengthen the things which remain, that are ready to die; for I find not thy works complete before my God (Rev. iii.2). Thus, because the works had not been found complete before his God, he foretold that those which remained, even such as had been done, were about to die. For, if that which is dead in us be not kindled into life, that which is retained as though still alive is extinguished too. They are to be admonished that it might have been more tolerable for them not to have laid hold of the right way than, having laid hold of it, to turn their backs upon it. For unless they looked back, they would not grow weak with any torpor with regard to their undertaken purpose. Let them hear, then, what is written, It had been better for them not to have known the way of righteousness than, after they have known it, to be turned backward (2 Pet. ii.21). Let them hear what is written; I would thou wert cold or hot: but, because than art lukewarm, and neither cold nor hot, I will begin to spue thee out of my mouth (Rev. iii.15, 16). For he is hot who both takes up and completes good purposes; but he is cold who does not even begin any to be completed. And as transition is made through lukewarmness from cold to heat, so through lukewarmness there is a return from heat to cold. Whosoever, then, has lost the cold of unbelief so as to live, but in no wise passes beyond lukewarmness so as to go on to burn, he doubtless, despairing of heat, while he lingers in pernicious lukewarmness, is in the way to become cold. But, as before lukewarmness there is hope in cold, so after cold there is despair in lukewarmness. For he who is yet in his sins loses not his trust in conversion: but he who after conversion has become lukewarm has withdrawn the hope that there might have been of the sinner. It is required, then, that every one be either hot or cold, lest, being lukewarm, he be spued out: that is, that either, being not yet converted, he still afford hope of his conversion, or, being already converted, he be fervent in virtues; lest he be spued out as lukewarm, in that he goes back in torpor from purposed heat to pernicious cold.