Matthew 7:24. Everyone, then, who hears these words of Mine and does them will be like a wise man who built his house upon the rock;
25. And the rain fell, and the floods came, and the winds blew and beat upon that house, but it did not fall, because it had been founded on the rock.
26. And everyone who hears these words of Mine and does not do them will be like a foolish man who built his house upon the sand;
27. And the rain fell, and the floods came, and the winds blew and beat against that house, and it fell; and great was the fall of it.
This is the conclusion and the end, on which everything depends: “Whoever not only hears this sermon with his ears but also does it is a wise and clever man.” The doctrine is a good and a precious thing, but it is not being preached for the sake of being heard but for the sake of action and its application to life. Particularly since we are always in danger from false prophets and miracle-workers, we should think it over and accept this teaching and warning, while we still hear it and have it, both as teachers and pupils. If we want to put it off until our little hour strikes and death and the devil come storming in with their rainstorms and tempests, then we have delayed too long. Therefore we must not only hear and be able, but actually do and fight.48
Those who say, “Lord, Lord,” hear it too. The pope, bishops, kings, and the whole world have been hearing it. The priests at Mass and the monks have read, sung, and chanted it every day. But no one has done it or preached it. They have remained with their false worship and their false miracles and have confirmed other people in them too. Though they have been listening a great deal and doing miracles, they have not done the will of God. They do not remain with the doctrine of Christ and genuine good works, but fall back on their own works, which are done without faith or love. Among all the monks and priests there is not a single authentic work to be found. They do not do any works to serve or help their neighbor but only to seek their own advantage. Therefore they completely lack faith, love, and patience. They really do nothing at all, as Christ says, though they hear the right teaching; for it does not get a grip on them, since their hearts are nothing but sand.
Nevertheless, as we have said, there is plenty of activity and teaching among them, even more than among the true preachers and Christians. This, too, gives the people the wrong impression. With his ascetic and spiritual life a hermit or a Carthusian seems to be doing much more than St. Paul or any true preacher and Christian. The outward masks of special works and worship are so dazzling that an ordinary Christian life seems pale by comparison. So they have no shortage of doing, teaching, and believing. “The difference is,” Christ says, “that they hear My teaching, but all they want to do is what they themselves have invented. I cannot keep them on the track of doing what I teach them.” If we Christians were as diligent in our works as they are in theirs, we would be nothing but saints. Still neither side really gets anywhere: we are lazy and indolent; they are entirely too active, but never in doing genuine works. And so, thank God, we still have the advantage, in that we have started believing and loving a little and are on the right track, however weak our progress may be.
Now He closes this with a beautiful analogy, showing the final outcome of both: “Everyone who hears and practices My teaching is a fine, smart builder, who does not build on sand but first finds a strong rock as a foundation. Once he has this, he builds on it so that his house may last and stand firm. Then when the storms and rains strike around it and above it, and when the floods and winds strike beneath it to wash away the ground and upset the house, it stands immovable against all of them as though it were defying them. But everyone who erects his building on sand will discover that it will stand only until the rain and the floods wash it away and the wind upsets it, so that it lies in a heap or collapses by itself.” With this analogy He intends to give us a faithful warning to be careful that we hold tight to His teaching and do not let go of Christ in our hearts, as our only sure Foundation (1 Cor. 3:11) and the Cornerstone of our salvation and blessedness (1 Peter 2:6), as St. Paul and St. Peter call Him on the basis of Isaiah 28:16. If we stand grounded and built on that, we shall remain impregnable. We can let the world and the devil and all the false teachers and schismatic spirits send rain and hail and slush on us and storm and rage around us with every kind of danger and trouble.
Those miserable and foolish people cannot have this assurance and certainty. They do not stand on the rock, that is, on the doctrine about Christ, but on the shifting sand of their own suppositions and dreams. When trouble comes and they have to battle against the devil and death, then they discover that they have put their trust in loose sand and that their stations and works cannot last. I myself have had the experience of seeing many such poor people, especially in monasteries. They really felt this, and finally the fright and terror of their conscience drove them crazy, and some of them remained in eternal despair. The reason was the fact that they had built on their own way of life, devotion, and good intentions and did not know anything about Christ. That sort of room was just equipped for the devil, and he could gleefully upset it and throw it all into a heap.
St. Bernard himself also had to feel this and admit it. He had led an extremely ascetic life with prayers, fasts, and chastisements, and there was nothing he lacked. He was an example for everyone else, and I know no one among the monks who wrote or lived better than he. And yet, when the anguish of death came upon him, he himself had to pronounce this judgment on his whole holy life: “Oh, I have lived damnably and passed my life shamefully!”49 “How so, dear St. Bernard? Have you not been a pious monk all your life? Are not50 chastity, obedience, preaching, fasting, and praying something valuable?” “No,” he says, “it is all lost and belongs to the devil.” Along comes the rain and the wind, pulling down the foundation and the floor and the building into one heap. Therefore he would have had to be damned eternally by his own judgment if he had not come to his senses through his loss, turned around, walked away from monkery, taken hold of a different foundation, clinging to Christ, and being preserved in the Creed that the children pray. As he says: “I am not worthy of eternal life, and I cannot obtain it by my own merit. Yet my Lord Christ has a double right to it: first, a right as the Lord and the heir to it from eternity; secondly, a right which He has won through His suffering and death. The first He keeps for Himself, the second He grants to me.” If they were saved, that is how all the monks and priests and everyone who claimed to be holy had to crawl out of their cowls and all their works and cling to Christ, though they found it distasteful to do so. It is hard for a man who has devoted his entire life to this self-made holiness and has depended on it to tear loose from it in one hour and to cast himself only upon Christ. Hence He warns and admonishes us to take hold of His teaching and to do it while we still have time, before the agony and the death pangs come over us.
So our dear Lord has finished this beautiful sermon. Now the evangelist concludes by saying that the whole world had to testify that this teaching was much different from any that they had been accustomed to hearing before.
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 (21:280). Saint Louis: Concordia Publishing House.