“In this epistle we thus find most abundantly the things that a Christian ought to know, namely, what is law, gospel, sin, punishment, grace, faith, righteousness, Christ, God, good works, love, hope, and the cross; and also how we are to conduct ourselves toward everyone, be he righteous or sinner, strong or weak, friend or foe—and even toward our own selves.
Moreover this is all ably supported with Scripture and proved by St. Paul’s own example and that of the prophets, so that one could not wish for anything more.
Therefore it appears that he wanted in this one epistle to sum up briefly the whole Christian and evangelical doctrine, and to prepare an introduction to the entire Old Testament.
For, without doubt, whoever has this epistle well in his heart, has with him the light and power of the Old Testament.
Therefore let every Christian be familiar with it and exercise himself in it continually.
To this end may God give Hs grace. Amen.”
–Martin Luther, “Preface to the Epistle of St. Paul to the Romans 1546 (1522),” Luther’s Works, Vol. 35: Word and Sacrament I, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann, vol. 35 (Philadelphia: Fortress Press, 1999), 35: 380.