Satan is raging and angry, but God is kindly disposed. Luther.
For God does not afflict the godly; He permits the devil to do this, as we see in the case of Job, whose children are killed by fire and his cattle by storms, not because God was angry with him, but because Satan was.
Therefore when a plague and other misfortunes assail us, we, too, should say that these are the works of Satan, that Satan is raging and is angry, but that God is merciful and is kindly disposed toward us because we believe in His Son.
And in this manner the saintly martyrs overcame death and all dangers; for they were sure that God was kind to them. But they concluded that their tortures and afflictions were due to magic and the devil, and were permitted by God for the purpose of testing their faith. Therefore they even rejoiced in their adversities and scoffed at Satan. We should do the same thing; but we are very frequently overcome by weakness, as the examples even of great saints prove. For Paul, too, is filled with fears and regains his courage when he sees the brethren (Acts 28:15). Such fear is not felt by the ungodly, for they are sure of God’s favor. Accordingly, even though some adversity befalls them, they smugly attribute this to Satan.
…these truths should be carefully impressed and taught, lest we yield to the flesh when we are tried or to our reason when we disregard the Word. For it is not God who torments you if you believe in Christ; it is the devil. He hates you and looks for opportunities to trouble you. But you will say: “I realize that I am a sinner. Therefore I am not a Christian. Therefore if any evil befalls me, it is sent by an angry God.” But this conclusion is false, for those who believe in the forgiveness of sins are Christians. Therefore if you believe in Christ, if you gladly hear His Word and receive it in faith, you are a true Christian, and your sins do not stand in the way. Hence if any misfortune befalls you, conclude boldly that it is from the devil and does not mean that God is unfriendly toward you, except insofar as He lets this happen as a trial, in order to put your faith to the test for your own good.
Learn from your own enemies and from the enemies of God that although the threats properly apply to them, they do not recognize this fact but appropriate, and comfort themselves with, the promises. You, too, must do this. For it is a disgrace for you to be ignorant of the true doctrine which you profess. You fear God and believe in God; therefore not the Law but the Gospel applies to you. But you forsake the Gospel and appropriate the Law, which concerns not you but the obdurate and the smug.
This is a spiritual weakness of which all the saints complain. Yet it is useful for repressing pride, in order that we may not put our trust in ourselves but may humble ourselves and learn to trust solely in the grace which God offers us in His Son. It is most certainly true that God is not angry with us; otherwise He would not give us the most excellent knowledge of His Son. Nor would He give us the Holy Spirit, whose first fruits we have received.
Luther, Genesis Lectures (19:14), AE 3: 264-265