What follows is a brief examination of each of these five theological slogans:
Sola Scriptura
By saying “Scripture Alone,” Christians acknowledge the Bible as God’s living Word. It is not the book that we worship but the Savior of Whom the book speaks. Jesus is God’s living Word to us. Thus, Luther’s explanation of the Third Commandment in the Large Catechism says: “The Word of God is the true holy thing above all things. Indeed, it is the only one we Christians acknowledge and have. Though we had the bones of all the saints or all the holy and consecrated vestments gathered together in one heap, they could not help us in the slightest degree, for they are all dead things that can sanctify no one. But God’s Word is the treasure that sanctifies all things. By it, all the saints themselves have been sanctified. At whatever time God’s Word is taught, preached, heard, read or pondered, there the person, the day, and the work are sanctified by it, not on account of the external work but on account of the Word which makes us all saints. Accordingly, I constantly repeat that all our life and work must be guided by God’s Word if they are to be God-pleasing and holy. Where that happens, the commandment is in force and is fulfilled.”
(Martin Luther, Book of Concord, The Large Catechism, “Third Commandment”)
Sola Gratia
By saying “Grace Alone,” Christians acknowledge that their salvation is given to saved sinners solely by of God’s mercy shown on account of Christ alone. God’s Grace is not only an object but is a part of His character. Rather, grace is part of who God is. It is an attitude with which He views us sinners as His children, by His great love, on account of Christ. The Reformer and colleague of Martin Luther, Philip Melanchthon, explains in his Loci Communes: “Grace signifies gracious acceptance, to the mercy of God, on account of the promise of Christ. As Paul says in Romans 5:15: ‘free gift by the grace.’ That is, we are called by the Holy Spirit and to eternal life. Further, the exclusive participle ‘only’ or ‘alone’ used with the word of grace, signifies that it is a gratuitously given remission of sins and reconciliation. The exclusive participle alone does not exclude our repentance and good works, but it rather eliminates the condition of all of our dignity and transfers the whole cause of our salvation to the benefit of the mercy shown us in Christ, so that it is clearly certain. Therefore, we are justified freely by His grace, that is, by God's mercy, so that we understand that we are pleasing to God, not on account of the dignity of our works, but on account of Christ.”
(Philip Melanchthon, The Loci Communes Theologici, 1535)