At this point, Paul reveals more fully what he alluded to in verse 1:17. What is the nature, then, of the faith required for salvation, in Paul's teaching? It is "apart from the Law" - it has nothing to do with the Law given at Mt. Sinai to the Jews, or the prophets' promise that redemption will come through observance of this Law.
Why, then, did God give the Law? What is the status of the Law?
When Paul writes, "There is no difference, for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus" - what does he mean by "no difference"? No difference between whom?
What does Paul mean by "redemption" and "salvation"?