Thus we can and should promise ourselves the things God has promised us with greater certainty, as if we held them in our hands. I have the kingdom of heaven, Baptism, the Word, and the Eucharist. These things pertain to me and are mine with greater certainty than this very life which I live. “And yet I do not feel it,” you will say. My answer is that you must learn with the fathers to hope for things not seen (Heb. 11:1) and to fix your eyes on heaven; you must learn with the fathers to ride on the clouds. The kingdom of heaven is yours; your sins are forgiven you through the blood of the Lamb. Only see to it that you believe. The promises are no joke. God does not lie. He says that you have been justified, sanctified, and saved. Thus these things are offered to us in the clearest and most glorious manner through the ministry of the Word. The only thing lacking is that we do not firmly assent to the Word and promises of God.
Luther’s works, vol. 8: Lectures on Genesis: Chapters 45-50