AE 5, on Genesis 26:16: Therefore we, too, should learn to wait for the Lord if we have His promise no matter what else happens, whether persecution instead of the presence of God befalls us or we feel His wrath instead of His grace. In spite of all, we should say: “I believe. I have been baptized. I have been absolved. I have God’s promise of grace and mercy. I have enough. Whether night, day, tribulation, or joy befalls me, I shall nevertheless not forfeit His mercy or lose courage.
“When faith begins, God does not forsake it; He lays the holy cross on our backs to strengthen us and to make faith powerful in us. The holy Gospel is a powerful Word. Therefore it cannot do its work without trials, and only he who tastes it is aware that it has such power. Where suffering and the cross are found, there the Gospel can show and exercise its power. It is a Word of life. Therefore it must exercise all its power in death. In the absence of dying and death it can do nothing, and no one can become aware that it has such power and is stronger than sin and death. Therefore the apostle says ’to prove you’; that is God inflicts no glowing fire or heat – cross and suffering, which make you burn – on you for any other purpose than ’to prove you,’ whether you also cling to His Word. This is recorded in Wisd. of Sol. 10:12 of Jacob: “God sent him an arduous contest, so that he might know that godliness is more powerful than anything.” God lays a cross on all believers in order that they may taste and prove the power of God – the power which they have taken hold of through faith” (Luther, TDP, Dec. 2).
Walther, Thesis XIII of Law & Gospel: In the ninth place, the Word of God is not rightly divided when one makes an appeal to believe in a manner as if a person could make himself believe or at least help towards that end, instead of preaching faith into a person’s heart by laying the Gospel promises before him.
We do not escape testing and temptation because of our faith. Faith is rather the courage to endure the old world and to call upon God, certain that God will hear and answer even though he may at times seem not to do so (Bayer, Living by Faith, 77).
Under no obligation and without any condition, God promises communion, communion through and beyond death. The justification of the ungodly, the resurrection of the dead, and creation out of nothing all happen through this promise and pledge alone. The promise of God lets us live by faith (Bayer, Living by Faith, 80).