"I am not ashamed of the gospel, for it is the power of God to save whoever believes, the Jew first, and also the Greek. For the righteousness of God is revealed therein on the basis of faith, for faith, as it is written, But the just shall live by faith." Romans 1. 16, 17
Europe was at that time anxious about death. Everyone was trying to "die in good standing".
Luther enters the convent to seek the assurance of salvation ; but he despairs : "I thought it was my salvation every time I felt the lust of the flesh."
He taught theology from 1512 to 1516. He then wanted to unravel the mystery of a Paulian expression that had troubled him a lot : "the justice of God revealed on the principle of faith". He is first revolted against God : in A.T. he gives his people a law impossible to fulfill, in the gospel he comes to ask for accounts. Now Luther understands that this justice is not the legal authority that condemns guilty sinners, but the gift that God gives to the one who believes. This righteousness declares just one who recognizes himself as incapable of pleasing God and who expects with faith to him.
He writes : "When I looked at him on the cross, I believed that Christ was for me like lightning." He adds : "Lord, you are my righteousness, but I am your sin: you have taken what was mine, and you have given me what I was not."
He embarks on the fight for the truth. He writes : "My duty was to speak, and I would rather excite the wrath of the world than God's." What drives him to act is the sale of "indulgences".
In fact, the Catholic Church proposed the merits of the saints and of Jesus Christ as a means of attaining salvation ; they could be acquired with penances or money. This revolts Luther, he wants to warn his contemporaries. He denounces these fatal errors in the 95 theses posted at the door of the church of Wittenberg October 31, 1517. Printers, religious, pilgrims will undertake to spread quickly across Europe. The movement of the Reformation was born.
Luther paved the way for this work of the Spirit, of which we are the beneficiaries today.
Source (To please the Lord)