Martin Luther's Preface to Romans: The Providence of God

But God is steadfast; his providence will not fail, and no one can prevent its realization. Therefore we have hope against sin. --Martin Luther

Obviously, Luther did not reject divine sovereignty in salvation.  But he rejected the idea that predestination to both election and reprobation should undermine our confidence in God's promises.  If anything predestination gives us assurance that God will save us.  The only individuals who need fear reprobation are unbelievers.  If God were not for us we would be overwhelmed by sin.  Martin Luther says we are not to speculate about whether or not we might not be saved or whether or not we may be reprobate:

In chapters 9, 10 and 11, St. Paul teaches us about the eternal providence of God. It is the original source which determines who would believe and who wouldn't, who can be set free from sin and who cannot. Such matters have been taken out of our hands and are put into God's hands so that we might become virtuous. It is absolutely necessary that it be so, for we are so weak and unsure of ourselves that, if it depended on us, no human being would be saved. The devil would overpower all of us. But God is steadfast; his providence will not fail, and no one can prevent its realization. Therefore we have hope against sin.

But here we must shut the mouths of those sacrilegious and arrogant spirits who, mere beginners that they are, bring their reason to bear on this matter and commence, from their exalted position, to probe the abyss of divine providence and uselessly trouble themselves about whether they are predestined or not. These people must surely plunge to their ruin, since they will either despair or abandon themselves to a life of chance.

You, however, follow the reasoning of this letter in the order in which it is presented. Fix your attention first of all on Christ and the Gospel, so that you may recognize your sin and his grace. Then struggle against sin, as chapters 1-8 have taught you to. Finally, when you have come, in chapter 8, under the shadow of the cross and suffering, they will teach you, in chapters 9-11, about providence and what a comfort it is. [The context here and in St. Paul's letter makes it clear that this is the cross and passion, not only of Christ, but of each Christian.] Apart from suffering, the cross and the pangs of death, you cannot come to grips with providence without harm to yourself and secret anger against God. The old Adam must be quite dead before you can endure this matter and drink this strong wine. Therefore make sure you don't drink wine while you are still a babe at the breast. There is a proper measure, time and age for understanding every doctrine.

God's peace,

Charlie


Click here to read Luther's preface:  Martin Luther's Commentary on the Bible