But as after the struggle the slanderous foe dare not give vent to any such murmur as this, he admired that he was vanquished by his strength and not by that of God; although too we must not hold that the grace of God was altogether wanting to him, which gave to the tempter a power of tempting in proportion to that which it knew that he had of resisting, without protecting him from his attacks in such a way as to leave no room for human virtue, but only providing for this; viz., that the most fierce foe should not drive him out of his mind and overwhelm him when weakened, with unequal thoughts and in an unfair contest. But that the Lord is sometimes wont to tempt our faith that it may be made stronger and more glorious, we are taught by the example of the centurion in the gospel, in whose case though the Lord knew that He would cure his servant by the power of His word, yet He chose to offer His bodily presence, saying: "I will come and heal him:" but when the centurion overcame this offer of His by the ardour of still more fervent faith, and said: "Lord, I am not worthy that Thou shouldest come under my roof: but speak the word only and my servant shall be healed," the Lord marvelled at him and praised him, and put him before all those of the people of Israel who had believed, saying: "Verily, I say unto you, I have not found so great faith in Israel."  For there would have been no ground for praise or merit, if Christ had only preferred in him what He Himself had given. And this searching trial of faith we read that the Divine righteousness brought about also in the case of the grandest of the patriarchs; where it is said: "And it came to pass after these things that God did tempt Abraham."  For the Divine righteousness wished to try not that faith with which the Lord had inspired him, but that which when called and enlightened by the Lord he could show forth by his own free will. Wherefore the firmness of his faith was not without reason proved, and when the grace of God, which had for a while left him to prove him, came to his aid, it was said: "Lay not thine hand on the lad, and do nothing unto him: for now I know that thou fearest the Lord, and for my sake hast not spared thy beloved son."  And that this kind of temptation can befall us, for the sake of proving us, is sufficiently clearly foretold by the giver of the Law in Deuteronomy: "If there rise in the midst of you a prophet or one that saith he hath seen a dream, and foretell a sign and wonder; and that come to pass which he spoke, and he say to thee: Let us go and serve strange gods which ye know not, thou shalt not hear the words of that prophet or dreamer; for the Lord your God surely trieth thee, whether thou lovest Him with all thine heart, and keepest His Commandments, or no."  What then follows? When God has permitted that prophet or dreamer to arise, must we hold that He will protect those whose faith He is purposing to try, in such a way as to leave no place for their own free will, where they can fight with the tempter with their own strength? And why is it necessary for them even to be tried if He knows them to be so weak and feeble as not to be able by their own power to resist the tempter? But certainly the Divine righteousness would not have permitted them to be tempted, unless it knew that there was within them an equal power of resistance, by which they could by an equitable judgment be found in either result either guilty or worthy of praise. To the same effect also is this which the Apostle says: "Therefore let him that thinketh he standeth, take heed lest he fall. There hath no temptation taken you but such as is common to man. But God is faithful, who will not suffer you to be tempted above that ye are able, but will with the temptation make also a way of escape that ye may be able to bear it."  For when he says "Let him that standeth take heed lest he fall" he sets free will on its guard, as he certainly knew that, after grace had been received, it could either stand by its exertions or fall through carelessness. But when he adds: "there hath no temptation taken you but what is common to man" he chides their weakness and the frailty of their heart that is not yet strengthened, as they could not yet resist the attacks of the hosts of spiritual wickedness, against which he knew that he and those who were perfect daily fought; of which also he says to the Ephesians: "For we wrestle not against flesh and blood, but against principalities, against powers, against the world-rulers of this darkness, against spiritual wickedness in heavenly places."  But when he subjoins: "But God is faithful who will not suffer you to be tempted above that ye are able," he certainly is not hoping that the Lord will not suffer them to be tempted, but that they may not be tempted above what they are able to bear. For the one shows the power of man's will, the other denotes the grace of the Lord who moderates the violence of temptations. In all these phrases then there is proof that Divine grace ever stirs up the will of man, not so as to protect and defend it in all things in such a way as to cause it not to fight by its own efforts against its spiritual adversaries, the victor over whom may set it down to God's grace, and the vanquished to his own weakness, and thus learn that his hope is always not in his own courage but in the Divine assistance, and that he must ever fly to his Protector. And to prove this not by our own conjecture but by still clearer passages of Holy Scripture let us consider what we read in Joshuah the son of Nun: "The Lord," it says, "left these nations and would not destroy them, that by them He might try Israel, whether they would keep the commandments of the Lord their God, and that they might learn to fight with their enemies."  And if we may illustrate the incomparable mercy of our Creator from something earthly, not as being equal in kindness, but as an illustration of mercy: if a tender and anxious nurse carries an infant in her bosom for a long time in order sometime to teach it to walk, and first allows it to crawl, then supports it that by the aid of her right hand it may lean on its alternate steps, presently leaves it for a little and if she sees it tottering at all, catches hold of it, and grabs at it when falling, when down picks it up, and either shields it from a fall, or allows it to fall lightly, and sets it up again after a tumble, but when she has brought it up to boyhood or the strength of youth or early manhood, lays upon it some burdens or labours by which it may be not overwhelmed but exercised, and allows it to vie with those of its own age; how much more does the heavenly Father of all know whom to carry in the bosom of His grace, whom to train to virtue in His sight by the exercise of free will, and yet He helps him in his efforts, hears him when he calls, leaves him not when he seeks Him, and sometimes snatches him from peril even without his knowing it.