The kingdom of Christ is realized where nothing but comfort and the forgiveness of sins reign not only in words to proclaim it, which is also necessary; but also in deed.
"Then behold, they brought to Him a paralytic lying on a bed. When Jesus saw their faith, He said to the paralytic, “Son, be of good cheer; your sins are forgiven.” (Matthew 9:2)
These words show and contain in brief what the kingdom of Christ is, namely, this sweet voice, these motherly and fatherly words penetrating our inmost soul: "Your sins are forgiven." In no other sense are we to view the kingdom of Christ, so far as it is understood, then how we are to live before God. As you, beloved, well know that our highest duty is rightly to establish the conscience that we may know how we stand before God and our neighbor. Therefore, we must also hold fast to these words and become accustomed to the expression: "Son, be of good cheer, your sins are forgiven", and like sayings of which the Gospel is full.
From this it follows that the kingdom of Christ is realized where nothing but comfort and the forgiveness of sins reign not only in words to proclaim it, which is also necessary; but also in deed, as we shall see in this example. For he did not only speak these words into the ear of this sick man; but he also forgave his sins and comforted him. This knowledge is proper for us Christians to know. It is indeed easily and quickly said and heard; but when it comes to the test the light is early extinguished, and Satan soon leads us astray; as you here observe that the scribes undertake to destroy this knowledge.
I have before often said and will always say, that you should beware and properly learn the character and nature of the kingdom of Christ. For you know how reason is inclined in its every movement to fall from faith and from this knowledge to works. But here you see no works at all, no merit, here there is neither command nor law; there is nothing more than the offering of Christ's assistance, his comfort and his grace, only kindness meets the man sick of the palsy.
Therefore, if the kingdom of Christ is to grow, we must keep the law out of it, and not be busy with works; for it is not in harmony with it to say: Go out and run hither and thither and atone for your sins; you must observe and do this and that, if you will be free from sin; but directly without any work and law, out of pure grace, your sins are forgiven. Therefore, it is beyond the sphere of the kingdom of Christ to urge the people with the law.
But we receive such things only with the ear and on the tongue, and it enters not into the depth of the heart; for sin at all times still hangs about our necks, it clings firmly to us, as St. Paul speaks of this in Romans 7:18-19. But in death we will experience it. Of this class are at present our fanatics who boast of the Holy Spirit, and pretend they would do better, some of whom are also in our midst, listen to us and contend that it is not enough for us to preach only faith and love. They say, you must do better and climb much higher. How high then must I climb?
Thus I say, my friends, and would beseech you not to esteem that spirit great who proposes to you any kind of work, call it what you may, even if it would raise the dead, which they have not yet been able to do. But by this you shall truly experience which spirits are of God. and which are not. For if you give me a work to do, it is not the Holy Spirit who does it; but he goes and first brings me the grace of Christ, and then leads me to works. For thus he speaks: Thy sins are forgiven, be of good cheer, and the like. He does not first insist on works, but first leads up to God through his sweet Word and grace, and does not immediately refer you to do some work; later you will find works enough to do unto your neighbor.
But the fanatics soon torment us with works, and profess to have a nobler spirit; they urge and insist upon our doing something first of all, and permit faith and love to be overlooked. This of course is not of the Holy Spirit. Christ first takes possession of the conscience, and when it is right in faith toward God, then he also directs us to do works toward our neighbor. But he first highly extols faith and keeps works in the background.
I say this: Even if it were a work which God at this present hour commanded, I would not so insist upon it and condemn those who do not immediately obey it; and would find him some kind of protection, as that he is yet perhaps weak, and thus spread over him the kingdom of grace. Let us be conscious of the fact that the work among them is directed to God, and not toward our neighbor. They make their works a necessity and say: If you do this, then you are a Christian; if you will not do it, you are no Christian. Where this or that is done there are Christians. And the fame follows their work, that they want to be esteemed better than others.
Now you have the true light, therefore be warned. Prove the spirits. We do not wish to prefer ourselves, as these persons do; but we boast in this, that we hear the Word, "Son, be of good cheer, your sins are forgiven." I know that I have a gracious God; but these spirits cannot do this. Even if the works were good, the forcing and compelling must remain in the background. Let them then keep quiet about setting us an example by their crazy works. The kingdom of Christ consists in finding all our praise and boast in grace.
This is an excerpt from a collection of public domain sermons given by Martin Luther.