You may have heard of the "5 solas". "Sola" is "alone" in Latin, so the Reformers had these five "alones": sola fide, sola gratia, solus Christus, sola scriptura, and soli Deo gloria. Okay, in English, we are saved by grace alone through faith alone in Christ alone. We are ruled by Scripture alone and all glory goes to God alone. All well and good. Except they aren't true. Well, not true in the sense of "alone". And this, I think, is the cause of some confusion with some people.
The easy one first -- soli Deo gloria. Is it not true that God gets all the glory. Well, mostly. We do know, for instance, that God's plan is to predestine some "to be conformed to the image of His Son" (Rom 8:29). "And those whom He predestined He also called, and those whom He called He also justified, and those whom He justified He also glorified." (Rom 8:30) So there is certainly a sense in which God's people will be "glorified". In the end, however, God gets the glory for that, so let's let that one go.
One of the most controversial is sola scriptura. What do we mean? Does it mean that the Bible is the sole source for truth? No, it doesn't. Then in what sense is Scripture "sola" -- alone? Well, by the term we mean that as the Word God breathed, Scripture is our sole authority on matters of faith and practice. Not on math, science, or biology. Not on politics, psychology, or economics. But when it comes to the Christian faith and how we ought to practice that faith, Scripture, as God's Word, is our sole authority. (Of course, this may have an impact on math, politics, economics, or the like, but you get what I'm saying, right?)
So, two of these "solas", as it turns out, are not strictly "alone". What we're finding is that they are "alone" in the sense that they exclude something specific. We give all glory to God and no one else. Others are excluded. Scripture is our sole authority in matters and faith and not the Roman Catholic Church, the priesthood, or the enlightened pentecostal down the street. This same idea works out in the other three.
We are saved by grace alone through faith alone in Christ alone. Indeed, this is almost word for word from Scripture. Except, of course, the "alones" aren't in there. So we read, "For by grace you have been saved through faith. And this is not your own doing; it is the gift of God." (Eph 2:8) This is true. Saved by grace through faith. Notice, however, that it doesn't say "in Christ". That's easily resolved, of course, but it's not in there. And this is significant for this discussion. You see, we are not saved by faith alone. You can see it in the phrase itself. We are saved by grace through faith in Christ. That's three things, not "alone". Scripture says, "The demons believe—and shudder!" (James 2:19) Faith alone saves no one. What, then, do we mean by sola fide? We mean that we are saved through faith apart from works. That's the intent. It is, in fact, critical. "Now to the one who works, his wages are not counted as a gift but as his due. And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness." (Rom 4:4-5) It is the distinctive of Christianity. We are not saved by works; we are saved by faith.
But not faith alone. We are saved by grace, too. How does that work? What is the phrase sola gratia intended to convey? It is intended, again, to exclude something. What? It excludes merit. "But if it is by grace, it is no longer on the basis of works; otherwise grace would no longer be grace." (Rom 11:6) We are saved on the pure kindness of God apart from any value in ourselves.
That leaves us with solus Christus. Clearly we are saved by grace through faith, so "alone" still doesn't quite apply, so what is intended here? As I've said, faith alone saves no one. If it did, "I believe I'll have another beer" would be a saving faith. Trust me; it's not. No, in order for us to be saved, there must be grace from someone and there must be faith in someone and that someone must be the right someone. Thus, solus Christus means we are saved by faith in Christ and in no other. It is a reference to the exclusivity of the Christian faith. As Peter told the crowds, "There is salvation in no one else, for there is no other name under heaven given among men by which we must be saved." (Acts 4:12)
That about rounds it up. While these solas are not actually alone, it is true that we are to live our lives to God's glory alone. It is true that Scripture is our sole authority in matters of faith and practice. It is true that we are saved through faith apart from works by grace apart from merit in Christ and no other. And when you think it all through, you find that these are quite comprehensive. I, for one, am glad for the five not-quite solas.