5 Return with me to that captive, return with me to my proposition. “The Law alarms him that relies on himself, grace assists him who trusts in God.” For look at that captive. “He sees another law in his members resisting the law of his mind, and leading him captive in the law of sin, which is in his members.” Lo, he is bound, lo, he is dragged along, lo, he is led captive, lo, he is subjected. What has that profited him, “You shall not lust”? He has heard, “You shall not lust;” that he might know his enemy, not that he might overcome him.
“For he had not known concupiscence,” that is, his enemy, “unless the Law had said, You shall not lust.” Now you have seen the enemy, fight, deliver yourself, make good your liberty, let the suggestions of pleasure be kept down, unlawful delight be utterly destroyed. Arm yourself, you have the Law, march on, conquer if you can. For what good is it that through the little portion of God's grace you have already, you “delight in the Law of God after the inward man? But you see another law in your members resisting the law of your mind;” not “resisting” yet powerless for anything, but “leading you captive in the law of sin.”
Behold, whence to you who fearest that “plentifulness of sweetness is hidden!” to him that fears it “is hidden,” how is it wrought out for him that “trusts”? Cry out under your enemy, for that you have an assailant, you have an Helper too, who looks upon you as you fight, who helps you in difficulty; but only if He find you “trusting;” for the proud He hates. What then will you cry under this enemy? “Wretched man that I am!” You see it already, for you have cried out. Be this your cry, when haply you are distressed under the enemy, say ye, in your inmost heart say, in sound faith say, “Wretched man that I am!”
Wretched that I am! “Therefore wretched,” because “I.” “Wretched man that I am,” both because “I,” and because “man.” For “he is disquieted in vain.” For though “man walks in the Image;” yet, “wretched man that I am, who shall deliver me from the body of this death?” Wilt you yourself? Where is your strength, where is your confidence? Of a surety you both cry out, and are silent; silent, that is, from extolling yourself, not from calling upon God. Be silent, and cry out. For God Himself too is both silent, and cries aloud; He is silent from judgment, He is not silent from precept; so be too silent from elation, not from invocation; lest God say to you, “I have been silent, shall I be silent always?” Cry out therefore, “O wretched man that I am!”
Acknowledge yourself conquered, put your own strength to shame, and say, “Wretched man that I am, who shall deliver me from the body of this death?” What did I say above? The Law alarms him that relies upon himself. Behold, man relied upon himself, he attempted to fight, he could not get the better, he was conquered, prostrated, subjugated, led captive. He learned to rely upon God, and it remains that him whom the Law alarmed while he relied upon himself, grace should assist now that he trusts in God.
In this confidence he says, “Who shall deliver me from the body of this death? The grace of God by Jesus Christ our Lord.” Now see the sweetness, taste it, relish it; hear the Psalm, “Taste and see that the Lord is sweet.” He has become sweet to you, for that He has delivered you. You were bitter to your own self, when you relied upon yourself. Drink sweetness, receive the earnest of so great abundance.
Source: Sermons on Selected Lessons of the New Testament (New Advent)