But if you say: What, then, shall I do if I cannot feel such distress or experience hunger and thirst for the Sacrament? Answer: For those who are so minded that they do not realize their condition I know no better counsel than that they put their hand into their bosom to ascertain whether they also have flesh and blood. And if you find that to be the case, then go, for your good, to St. Paul’s Epistle to the Galatians, and hear what sort of a fruit your flesh is: Now the works of the flesh (he says in Galatians 5:19-21) are manifest, which are these: Adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envyings, murders, drunkenness, revelings, and such like.
Therefore, if you cannot feel it, at least believe the Scriptures; they will not lie to you, and they know your flesh better than you yourself. Yea, St. Paul further concludes in Rom. 7:18: “I know that in me, that is, in my flesh, dwelleth no good thing.” If St. Paul may speak thus of his flesh, we do not propose to be better nor more holy. But that we do not feel it is so much the worse; for it is a sign that there is a leprous flesh which feels nothing, and yet the leprosy rages and keeps spreading. Yet, as we have said, if you are quite dead to all sensibility, still believe the Scriptures, which pronounce sentence upon you. And, in short, the less you feel your sins and infirmities, the more reason have you to go to the Sacrament to seek help and a remedy.
In the second place, look about you and see whether you are also in the world, or if you do not know it, ask your neighbors about it. If you are in the world, do not think that there will be lack of sins and misery. For only begin to act as though you would be godly and adhere to the Gospel, and see whether no one will become your enemy, and, moreover, do you harm, wrong, and violence, and likewise give you cause for sin and vice. If you have not experienced it, then let the Scriptures tell you, which everywhere give this praise and testimony to the world.
Besides this, you will also have the devil about you, whom you will not entirely tread under foot, because our Lord Christ Himself could not entirely avoid him. Now, what is the devil? Nothing else than what the Scriptures call him, a liar and murderer. A liar, to lead the heart astray from the Word of God, and to blind it, that you cannot feel your distress or come to Christ. A murderer, who cannot bear to see you live one single hour. If you could see how many knives, darts, and arrows are every moment aimed at you, you would be glad to come to the Sacrament as often as possible. But there is no reason why we walk so securely and heedlessly, except that we neither think nor believe that we are in the flesh, and in this wicked world or in the kingdom of the devil.
Therefore, try this and practice it well, and do but examine yourself, or look about you a little, and only keep to the Scriptures. If even then you still feel nothing, you have so much the more misery to lament both to God and to your brother. Then take advice and have others pray for you, and do not desist until the stone be removed from your heart. Then, indeed, the distress will not fail to become manifest, and you will find that you have sunk twice as deep as any other poor sinner, and are much more in need of the Sacrament against the misery which unfortunately you do not see, so that, with the grace of God, you may feel it more and become the more hungry for the Sacrament, especially since the devil plies his force against you, and lies in wait for you without ceasing to seize and destroy you, soul and body, so that you are not safe from him one hour. How soon can he have brought you suddenly into misery and distress when you least expect it!
The Large Catechism of Martin Luther, Part 5, paragraphs 75-84