From the Word
44 Then he said to them, “These are my words which I spoke to you, while I was still with you, that everything written about me in the law of Moses and the prophets and the psalms must be fulfilled.” 45 Then he opened their minds to understand the scriptures, 46 and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, 47 and that repentance and forgiveness of sins should be preached in his name to all nations, beginning from Jerusalem. 48 You are witnesses of these things.
The gospel is the preaching of repentance and remission of sins. It should not be preached in a corner, but before all men, whether it be received or not, for it is to spread even farther that it may be heard and bear fruit. We are not to be offended though few receive it, nor say it has been given in vain. We should be content that Christ has commanded us to preach it in all the world, that he who will may receive it.
By repentance Christ means a change for the better; not what we have called repentance, when one scourges and chastises himself and does penance to atone for his sin, or when the priest imposes this or that upon any one for penance. Scripture does not speak of it in this sense. Repentance signifies a change and reformation of the whole life; so that when one knows that he is a sinner and feels the iniquity of life, he desists from it and enters upon a better course of life in word and deed, and does it from the heart.
But we should preach also forgiveness of sins. This signifies that the gospel should be preached, which declares unto all the world that in Christ the sins of all the world are swallowed up, that he suffered death to put away sin from us, and arose to blot it out. All this he did, that whoever believeth should have the comfort and assurance that it is reckoned unto him even as if he himself had done it. This continues as long as we live until the day of judgment.
Forgiveness is so great and powerful that God not only forgives your past sins, but forgives also the sins you will yet commit. He will not condemn us for our daily infirmities, but forgives all, in view of our faith in him, if we only strive to press onward and get rid of sin. Repentance in his name is done when in those who believe in Christ God through that faith works a change for the better, not for a moment, nor for an hour, but for their whole life. A Christian is not perfectly nor instantaneously cleansed, but the reformation and change continues as long as he lives. Nothing will be accomplished except in Christ’s name. That alone has power to save.
Luther, Martin, and John Sander. Devotional Readings from Luther’s Works for Every Day of the Year. Augustana Book Concern, 1915, pp. 409–10.
Today's video was made in 2021 so references in the video to days and dates may be askew in the year in which you are listening. However, the Luther reading is, indeed, for this day in the year.