I learned the gospel from Martin Luther:
“…He who wants to be saved and go to heaven when he dies must think and say: ‘Have mercy on me, gracious God. I am a poor, sinful being who has merited nothing but wrath. But whether my life was good or evil, I know that I need not doubt that I was baptized and named a Christian for the remission of sins; that Christ my Lord was born, suffered, and died, and was raised from the dead for me; that He gave me His holy body and blood as food for the strengthening of my faith; and that I have been absolved and relieved of my sin in the name and by the power of Christ.’ Such a heart and such a faith cannot fare adversely or be lost any more than God’s Word can fail or be false. This I can guarantee you, since God Himself guarantees it to you through His Word.”
From Luther’s Works, American Edition; ed. Jaroslav Pelikan (Saint Louis: Concordia Publishing House, 1961), XXIV.222.