Matthew 5:16. Let your light so shine before men that they may see your good works and give glory to your Father who is in heaven.
See the earnestness with which He puts the exhortation. He would not have to do this if there were not great urgency and need. It is as though He were saying: “They will try to darken your light because they cannot stand it. But be bold and courageous against them. If you just keep yourselves from crawling under a bushel and if you discharge your ministry faithfully, I will see to it that they do not succeed in putting it out.” For this much is sure: So long as a Christian preacher holds on and sticks to his business, despising the world’s abuse and persecution, the ministry will abide and the Gospel cannot fail; for some will always stand firm and abide, as indeed there must always be some that abide, until Judgment Day.
The statement “that they may see your good works and give glory to your Father who is in heaven” is in accordance with St. Matthew’s way of speaking; he usually talks this way about works. Neither in his Gospel nor in those of the other two evangelists, Mark and Luke, do we find such a great emphasis upon the profound doctrine of Christ as we do in St. John and St. Paul; instead, we find them talking and exhorting about good works. Of course, it is appropriate that in Christendom both should be preached, yet each in keeping with its nature and value. First and highest is the proclamation about faith and Christ, then comes the emphasis upon works. The evangelist John discussed the chief article thoroughly and powerfully, and hence he is properly regarded as the highest and foremost evangelist. For this reason, Matthew, Luke, and Mark considered and emphasized the other issue, to make sure that it was not forgotten. On this issue, then, they are better than John, while he is better than they on the other one.
But you dare not look at the statements and instructions about works in a manner that separates faith from them, the way our blind theologians mutilate them. You must always connect them with faith and incorporate them in it, making them a result and a concomitant of faith, praised and called “good” for its sake, as I have often taught. Here, too, when He says, “that they may see your good works,” you must not merely think of the sort of faith-less works that the good works of our clergy have been until now, but of the sort of works that faith performs and that are impossible apart from faith. What He calls “good works” here is the exercise, expression, and confession of the teaching about Christ and faith, and the suffering for its sake. He is talking about works by which we “shine”; but shining is the real job of believing or teaching, by which we also help others to believe.
What He means, therefore, is the highest and best kind of works, works whose necessary consequence it must be, as He says here, “that the heavenly Father is honored and praised.” For this teaching or preaching deprives us of every claim to holiness, and it says that we have nothing good in us to brag about. In addition, it instructs the conscience about its relation to God, showing it His grace and mercy and the whole Christ. That is the real revelation and praise of God and at the same time the real sacrifice and worship. These are the works that should be first and foremost. They should be followed by those pertaining to our relations with our neighbor in what are called “works of love,” which shine, too, but only insofar as they are ignited and sustained by faith.
Now you can draw the conclusion for yourself that Matthew does not have in mind the ordinary works that people should do for one another out of love, which he talks about in Matthew 25:35 ff. Rather is he thinking principally about the distinctly Christian work of teaching correctly, of stressing faith, and of showing how to strengthen and preserve it; this is how we testify that we really are Christians. The other works are not such a reliable criterion, since even sham Christians can put on the adornment and cover of big, beautiful works of love. But the true teaching and confession of Christ is impossible without faith; as St. Paul says (1 Cor. 12:3): “No one can say, ‘Jesus is Lord,’ except by the Holy Spirit.” No sham Christian or schismatic spirit can understand this teaching. How much less can he truly preach it and confess it! Even though he might perceive the words and imitate them, still he does not hold to them or keep them pure. His preaching always betrays the fact that he does not have it straight. He slobbers all over it by stealing the honor from Christ and claiming it for himself.
Thus the most reliable index to a true Christian is this: if from the way he praises and preaches Christ the people learn that they are nothing and that Christ is everything. In short, it is the kind of work that cannot be clone in relation to one or two people, remaining hidden like other works. It has to shine and let itself be seen publicly, in front of the whole world. That is always why it alone is persecuted, for the world can tolerate other works. This also entitles it to be called a work through which our Father is recognized and praised. The other and less important works are not entitled to this, since they remain purely on the human level and belong to the Second Table of the Decalog.24 The works we are talking about now deal with the first three great commandments, which pertain to God’s honor, name, and Word. In addition, if they are to endure, they have to be verified and purified through persecution and suffering. They also have to be slandered before the world to keep them pure of any self-esteem or presumptuousness and to make them all the more praiseworthy before God, since this is really a slander of His honor and praise. That is also why they stand so firmly and why God defends them so powerfully, leading them through despite the raging and persecution of the world. Therefore we should also give these works a position of pre-eminence as the most important, followed by the others, which involve our relations with people. Thus both will have their due. First we should constantly teach and emphasize faith, and then we should live according to faith. In this way everything we do will be done in faith and from faith, as I have always taught.
Luther, M. (1999, c1956). Vol. 21: Luther's works, vol. 21 : The Sermon on the Mount and the Magnificat (J. J. Pelikan, H. C. Oswald & H. T. Lehmann, Ed.). Luther's Works (21:64). Saint Louis: Concordia Publishing House.