"‘Through the Spirit, by faith, we wait for the hope of righteousness’ (Galatians 5:5). This passage contains very important instruction and comfort. The instruction is that we are not justified through works, ceremonies, sacrifices, and the whole system of worship in the Mosaic Law, much less through human works and traditions, but through Christ alone. Whatever there is in us beside Him — whether it be intellect or will, activity or passivity, etc. — is flesh, not Spirit. Therefore whatever the world has that is very good and holy apart from Christ is sin, error, and flesh. And so circumcision, the observance of the Law, as well as the works, righteous observances, and vows of the monks and of all the self-righteous, are of the flesh. ‘But we,’ Paul says, ‘go far beyond all this to live in the Spirit, because through faith we hold to Christ, and in tribulation we wait by hope for that righteousness which we already posses by faith.’
"The comfort is this, that in your deep anxieties — in which your consciousness of sin, sadness, and despair is so great and strong that it penetrates and occupies all the corners of your heart — you do not follow your consciousness. For if you did, you would say: ‘I feel the violent terrors of the Law and the tyranny of sin, not only waging war against me again but completely conquering me. I do not feel any comfort or righteousness. Therefore I am not righteous but a sinner. And if I am a sinner, then I am sentenced to eternal death.’ But battle against this feeling, and say: ‘Even though I feel myself completely crushed and swallowed by sin and see God as a hostile and wrathful judge, yet in fact this is not true; it is only my feeling that thinks so. The Word of God, which I ought to follow in these anxieties rather than my own consciousness, teaches much differently, namely, that "God is near to the brokenhearted, and saves the crushed in spirit" (Ps. 34:18), and that "He does not despise a broken and contrite heart" (Ps. 51:17). And here Paul then teaches that through the Spirit, by faith, those who are justified do not yet feel the hope of righteousness but still wait for it.’
"When the Law accuses and sin terrifies you, and you do not feel anything except the wrath and judgment of God, do not despair on that account. But ‘take the armor of God, the shield of faith, the helmet of hope, and the sword of the Spirit’ (Eph. 6:13, 16, 17); and find out by experience what a good and brave warrior you are. By faith take hold of Christ, the Lord of the Law and of sin and of everything that accompanies them. When you believe in Him, you are justified — something that your reason and the consciousness of your heart do not tell you amid your temptation, but only the Word of God. Then, in the conflicts and fears that continually return to plague you, you should patiently look with hope for the righteousness that you have only by faith, though only in an incipient and imperfect form, until it is revealed perfectly and eternally in due time. ‘But I am not conscious of having righteousness, or at least I am only dimly conscious of it!’ You are not to be conscious of having righteousness; you are to believe it. And unless you believe that you are righteous, you insult and blaspheme Christ, who has cleansed you by the washing of water with the Word (Eph. 5:26) and who in His death on the cross condemned and killed sin and death, so that through Him you might obtain eternal righteousness and life. You cannot deny this, unless you want to be obviously wicked, blasphemous, and contemptuous of God, of all the divine promises, of Christ, and of all His benefits. Then you cannot deny either that you are righteous.
"Let us learn, therefore, that amid great and horrible terrors, when the conscience feels nothing but sin and supposes that God is wrathful and Christ is hostile, we must not consult the consciousness of our own heart. No, then we must consult the Word of God, which says that God is not wrathful, but that He has regard for those who are afflicted, are contrite in spirit, and tremble at His Word (Is. 66:2), and that Christ does not turn away from those who labor and are heavy-laden (Matt. 11:28) but revives them. Therefore this passage teaches clearly that the Law and works do not bring righteousness and comfort, but that this is achieved by the Spirit through faith in Christ; amid anxieties and tribulations He arouses hope, which endures and conquers evil. Very few people know how weak and feeble faith and hope are in cross and conflict; then faith and hope seem to be ‘a dimly burning wick’ (Is. 42:3), which a strong wind is about to blow out. But those who in hope believe against hope (Rom. 4:18) amid these conflicts and fears; that is, those who fight against the consciousness of sin and of the wrath of God by faith in the promise of Christ, eventually experience that this poor little spark of faith (as it seems to reason, because it is hardly aware of it) will become like elemental fire, which fills all heaven and swallows up all terrors and sins.
"Truly devout people have nothing dearer and more precious in the whole world than this doctrine; for those who hold to this know what the whole world does not know, namely, that sin and death, as well as other calamities and evils, both physical and spiritual, work out for the good of the elect. They also know that God is present most closely when He seems to be farthest away, and that His is most merciful and most the Savior when He seems most to be wrathful and to punish and condemn. They know that they have eternal righteousness, for which they look in hope as an utterly certain possession, laid up in heaven, when they are most aware of the terrors of sin and death; and that they are the lords of everything when they seem to be the poorest of all, according to the words ‘as having nothing, and yet possessing everything’ (2 Cor. 6:10). This is what Scripture calls gaining comfort through hope. But this art is not learned without frequent and great trials." (Luther’s Works, Volume 27, CPH 1963; alt.)