We're beating the repentance drum this week, of course that could mean the total regeneration of the person, or the turning from a particular sin, or the first part of the proclamation of the gospel in general...

Jonah 3:1-5, 10

When God saw what they did, how they turned from their evil ways, God changed his mind about the calamity that he had said he would bring upon them; and he did not do it.
--Jonah 3:10

Verse 10 is cited through editorial insert in Apology of the Augsburg Confession, Article 12: Repentance (AP 12.166) where Melanchthon says that the Ninevites are examples of true repentance--at least at this moment in time--because they took Jonah's call to repentance seriously.

Mark 1:14-20

...and saying, “The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news.”
--Mark 1:15

Verse 15 has several citations throughout the Book of Concord. Verse 15 is first quoted in Apology of the Augsburg Confession, Article 12: Repentance (AP 12.45) as Melanchthon begins to defend the reformers' argument that repentance consists of two parts: contrition and faith. In this verse, Jesus uses that very model by first calling people to turn from their sin and then believe in the good news of God in Jesus--that in Christ, our sins are forgiven. The second quote of verse 15 provides the background for Melanchthon's argument.

Verse 15 is next quoted in Smalcald Articles, Part 3, Article 3: Concerning Repentance (SA 3.3.4). Here Luther makes Melanchthon's argument by restating "repent, and believe in the good news" as "Become and act otherwise, and believe my promise." In this article, Luther sets the God's law together with God's promise to present the two-step idea of repentance.

Verse 15 also comes up in Formula of Concord, in both the Epitome and Solid Declaration. In the Epitome, verse 15 is cited as part of Article 5: Law and Gospel, Affirmative Thesis 5 (FC, Ep 5.6) as an example of the word "gospel" (although we have it as "good news") meaning the entire teaching of Christ that calls people both to repentance and also the forgiveness of sin.

The parallel section in the Solid Declaration—Article 5: Law and Gospel—calls out verse 15 twice (FC, SD 5.6, 8), but here it's used to make exactly the opposite point: the word "gospel" can also refer particularly to "the proclamation of the grace of God" (FC, SD 5.6). And similarly, repentance can mean the regeneration of a person or a turning from sin, as it does in this verse (FC, SD 5.8).

The final instance of verse 15 is a quote in Formula of Concord, Solid Declaration, Article 11: Election (FC, SD 11.67) as part of a long string of biblical quotes making the case that election to eternal life does not make sense without Jesus, whose life, ministry, death, resurrection, and ascension proclaims and shows God's will to all people.

TheoThru

Repentance is certainly not a once and done aspect of faith, but there are times when repentance and faith lead to remarkable and instantaneous actions--like walking away from your livelihood to follow some wandering teacher, or declaring that an entire city should perform acts of contrition. The discernment of spirits takes time, but moments of repentance do lead us into actions that might amaze those around us.

As a Christian, when would it be faithful to join Jonah is proclaiming God's judgment but not God's grace given to us in Jesus?
How do we rush too quickly to the good news without giving people a chance to repent?