(This post comes from 1517.org. It was written by Dr. Scott Keith, professor of theology at Concordia Irvine. You can find the original post here.)

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)

The Five Solas are:

• Sola Scriptura + Scripture Alone
• Sola Fide + Faith Alone
• Sola Gratia + Grace Alone
• Solus Christus + Christ Alone
• Soli Deo Gloria + To the Glory of God Alone

Sola Fide

“Faith Alone” saves the sinner. Faith is simply this: that we trust in the mercy of God on account of Christ alone as our only hope for salvation. This Paul says in his letter to the church at Rome: “What then shall we say that Abraham, our forefather according to the flesh, discovered in this matter? If in fact, Abraham was justified by works, he had something to boast about—but not before God. What does Scripture say? ‘Abraham believed God, and it was credited to him as righteousness.’ Now to the one who works, wages are not credited as a gift but as an obligation. However, to the one who does not work but trusts God who justifies the ungodly, their faith is credited as righteousness.” This faith, or trust, is not a work of our own, but a work of God within us. Thus, Martin Luther describes it this way: “Faith is and indeed must be a steadfastness (ein steadfasten) of the heart, which does not waver, wobble, shake, tremble, or doubt, but stands firm and is sure of its case. Do not think lightly of faith. It is a work that is of all works the most excellent and the most difficult. Through it alone you will be saved, even though you were obliged to do without all other works. For it is the work of God, not of man as Paul teaches in Ephesians 1:19: ‘and what is the immeasurable greatness of his power toward us who believe, according to the working of his great might.’ The other works He performs without our co-operation and through us; This alone He works within us and without our co-operation (sine nobis).”

(Luther, Martin, and Ewald M. Plass. What Luther Says, An Anthology. Saint Louis: Concordia Pub. House, 1959.)

Solus Christus

The Solus Christus, Christ Alone, of the Reformation is not just a theoretical matter; it is a question of life and death. The Scriptures present Jesus Christ as the only mediator between the holy God and sinful man. “For there is one God, and there is one mediator between God and men, the man Christ Jesus...” (1 Tim 2:5). God saves sinners propter Christum (on account of Christ alone), or solus Christus, only because of Christ. This is the heart of the matter. The Biblical claim is that the Law of God justly stands over the children of Adam. We are to love our neighbor in a particular way, the way described in the Ten Commandments. We cannot do this fully, even in the most outward way, not even as Christians with the Holy Spirit within us. But even if we could, it would still not be enough to justify us before God. The Law commands us to love our neighbor “from the heart.” “Having purified your souls by your obedience to the truth for a sincere brotherly love, love one another earnestly from a pure heart...” (1 Pet 1:22), without any vested interest on our part. Our obedience to the Law in the case of our neighbor is to be purely for our neighbor’s good, not in any way for our good. Anyone who does not measure up to this unchanging and non-negotiable standard of God’s Law stands under God’s just condemnation and wrath now and forever. Apart from a God-given, Law-satisfying mediator, every one of us stands before the righteous God as guilty and justly condemned by His just Law. Someone is going to have to satisfy divine justice, but we have not done so. Nor can we do so. Someone is going to have to pay the penalty for our sin because we cannot pay it. Thus Christ alone is our only hope for salvation.

(Modified from Rod Rosenbladt, Christ Alone)

Soli Deo Gloria

Soli Deo Gloria is the slogan that developed out of the Protestant Reformation to communicate the belief that it is God and God alone Who is to receive the glory for the wonders of His work of our redemption. By confessing Soli Deo Gloria, Christians acknowledge that all of the benefits of this earthly life, as well as the free gift of their salvation and the life everlasting, have come to them by God’s hand alone. This realization causes the Christian to proclaim that all the credit, merit, and glory ought to be ascribed solely to God. Even the Christian’s trust in the mercy of God on account of Christ, which we call faith, is a gift of God and not a part of any human work. As the Scriptures say: “For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek.” (Rom 1:16) And also, “So faith comes from hearing, and hearing through the word of Christ.” Also, “You did not choose me, but I chose you and appointed you that you should go and bear fruit and that your fruit should abide, so that whatever you ask the Father in my name, he may give it to you.” (John 15:16) Salvation, and every good gift is of the Lord from beginning to end. Yes, I must believe. Yes, I must respond. Yes, I must receive Christ. But for me to say “yes” to any of those things, my heart must first be changed by the eternal and efficacious power of God the Holy Spirit given through the proclaimed Word that is Christ. Thus we confess, Soli Deo Gloria.