Then again, wherefore was the building shaken? It was to arouse the jailer, to behold what was done, for he alone was worthy of being saved. And do thou too, behold, I pray, the exceeding greatness of the grace of Christ, for well were it in the midst of Paul's bonds to make mention also of the grace of God, nay indeed the very bonds themselves are of the gift and grace of God. Some indeed there are who complain “Why was the jailer saved?” and from those very circumstances, for which they ought to admire the loving-kindness of God they find fault with it. Nor is it anything to be wondered at. Such are those sickly persons, that find fault even with the food that nourishes them, which they ought to prize, and who affirm that honey is bitter: and those dimsighted persons who are darkened by the very thing which ought to enlighten them. Not that these effects arise from the nature of the objects themselves, but from the weakness of the persons who are unable to use them properly. What, however, was I saying? When they ought to be admiring God's loving-kindness, in that He took a man who had fallen into the most desperate wickedness, and was making him better, they find fault: “Why, how was it that he did not take the thing to be the work of witchcraft and of sorcery, and confine them the more closely, and cry out?” Many things conspired to prevent this; first, that he heard them singing praises to God. And sorcerers never would have been singing such hymns as those, for he heard them, it is said, singing praises unto God. Secondly, the fact, that they themselves did not take flight, but even withheld him from killing himself. Now had they done it for their own sake, they never would have remained still within; they would themselves have escaped first of all. Great again was their kindness also; they withheld the man from killing himself, even him who had bound them, thus all but saying unto him, “Truly, you bound us with all safety, and most cruelly, that you yourself might be loosed from the most cruel of all bonds.” For every one is shackled with the chains of his own sins; and those bonds are accursed, whereas these for Christ's sake are blessed, and worth many an earnest prayer. For that these bonds can loose those other bonds of sin, he showed to us by things which are matters of sense. Did you behold them released, who had been bound with iron? You shall see yourself also delivered from other galling bonds. These bonds, the prisoners' bonds, not those of Paul, I mean, are the effect of those other bonds, the bonds of sins. They who were confined within, were doubly prisoners, and the jailer himself was a prisoner. They indeed were bound both with iron and with sins, he with sins only. Them did Paul loose to assure the faith of him, for the chains which he loosed were visible. And thus too did Christ Himself; but rather in the inverse order. In that instance, there was a double palsy. What was it? There was that of the soul by sins, and also that of the body. What then did the Lord do? “Son,” says He, “be of good cheer, your sins are forgiven.” He first loosed the bonds of the real and true palsy, and then proceeds to the other: for when “certain of the Scribes said within themselves, This man blasphemes; Jesus, knowing their thoughts, said, Wherefore think ye evil in your hearts? For whether is easier, to say, Your sins are forgiven, or to say, Arise, and walk? But, that you may know that the Son of Man has power on earth to forgive sins, (then says he to the sick of the palsy,) Arise, and take up your bed, and go unto your house.” Having wrought the invisible miracle, He confirmed it by the visible, the spiritual by the bodily cure. And why did He do thus? That it might be fulfilled, which is spoken, “Out of your own mouth will I judge you, thou wicked servant.” For what said they? “None can forgive sins, but God alone.” Of course, therefore, no Angel, nor Archangel, nor any other created power. This you have yourselves confessed. And what then ought to be said? If I shall be shown to have forgiven sins, it is fully evident that I am God. However, He said it not thus, but what said He? “But that you may know that the Son of Man has power on earth to forgive sins; then says He to the sick of the palsy, Arise, and take up your bed, and go unto your house.” When therefore, He would say, I work the more difficult miracle, it is plain that there is no pretext left you, no room for gainsaying about the easier one. Hence it was that He wrought the invisible miracle first, because there were many gainsayers; and then He led them from the invisible to the visible itself.
Surely then the faith of the jailer was no light or hasty faith. He saw the prisoners. And he saw nothing, he heard nothing wrong; he saw that nothing was done by sorcery, for they were singing hymns unto God. He saw that every thing done proceeded from overflowing kindness, for they did not avenge themselves against him, although they had it in their power; for it was in their power to rescue both themselves and the prisoners, and escape; and if not the prisoners, at all events themselves; but they did not do this. Thus did they challenge his reverence, not only by the miracle, but also by their behavior. For how did Paul cry out? “He cried with a loud voice, saying, Do yourself no harm, for we are all here.” You see at once his freedom from vain-glory and arrogance, and his fellow-feeling. He said not, “It is for us these wonders have been wrought,” but as though he were merely one of the prisoners, he said, “For we are all here.” And yet, even though they had not before this loosed themselves, nor had done so by means of the miracle, still they might have been silent, and have set all that were bound at liberty. For had they held their peace, and had they not with their loud crying stayed his hand, he would have thrust the sword through his throat. Wherefore also Paul cried out, because he had been cast into the inner ward: as though he had said, “To your own injury have you done this, that you have thrust in so far those that could deliver you from the danger.” However they imitated not the treatment they had received at his hands; though, had he died, all would have escaped. You see that they chose rather to remain in bonds, than to suffer him to perish. Hence too might he reason within himself, “Had they been sorcerers, doubtless they would have set the others at liberty, and have released themselves from their bonds:” (for it is likely that many such had also been imprisoned.) He was the more amazed, in that having often received sorcerers in charge, he had yet witnessed nothing done like this. A sorcerer never would have shaken the foundations, so as to startle the jailer from sleep, and thus render his own escape more difficult.
Source: Homilies on Ephesians (New Advent)