Chapter 10.—Of the Praise of the Law.
Once more, in the praise of the law, what advantage is it to them that, in opposition to the Manicheans, they say the truth when they wish to bring men from that view to this which they hold falsely against the catholics? For they say, “We confess that even the old law, according to the apostle, is holy and just and good, and that this could confer eternal life on those that kept its commandments, and lived righteously by faith, like the prophets and patriarchs, and all the saints.” By which words, very craftily expressed, they praise the law in opposition to grace; for certainly that law, although just and holy and good, could not confer eternal life on all those men of God, but the p. 421 faith which is in Christ. For this faith worketh by love, not according to the letter which killeth, but according to the Spirit which maketh alive, to which grace of God the law, as it were a schoolmaster, leads by deterring from transgression, that so that might be conferred upon man which it could not itself confer. For to those words of theirs in which they say “that the law was able to confer eternal life on the prophets and patriarchs, and all saints who kept its commandments,” the apostle replies, “If righteousness be by the law, then has Christ died in vain.” 2793 “If the inheritance be by the law, then is it no more of promise.” 2794 “If they which are of the law be heirs, faith is made void, and the promise is made of none effect.” 2795 “But that no man is justified by the law in the sight of God, is evident: for, The just by faith liveth.” 2796 “But the law is not of faith: but The man that doeth them shall live in them.” 2797 Which testimony, quoted by the apostle from the law, is understood in respect of temporal life, in respect of the fear of losing which, men were in the habit of doing the works of the law, not of faith; because the transgressors of the law were commanded by the same law to be put to death by the people. Or, if it must be understood more highly, that “He who doeth these things shall live in them” was written in reference to eternal life; the power of the law is so expressed that the weakness of man in himself, itself failing to do what the law commands, might seek help from the grace of God rather of faith, seeing that by His mercy even faith itself is bestowed. Because faith is thus possessed, according as God has given to every one the measure of faith. 2798 For if men have it not of themselves, but men receive the Spirit of power and of love and of continence, whence that very same teacher of the Gentiles says, “For we have not received the spirit of fear, but of power, and of love, and of continence,” 2799 —assuredly also the Spirit of faith is received, of which he says, “Having also the same Spirit of faith.” 2800 Truly, then, says the law, “He who doeth these things shall live in them.” But in order to do these things, and live in them, there is necessary not law which ordains this, but faith which obtains this. Which faith, however, that it may deserve to receive these things, is itself given freely.