In pagan, heathen Greek, the word charis means FAVOR. It's a good, simple ancient concept that basically means someone is pleased with somebody else. The person doling out FAVOR is usually an important somebody, or else their FAVOR wouldn't be worth discussing. By the way, "merit" or "unmerit" often has nothing to do with it. Xerxes was pleased with a dinner. Herod was pleased with a dance. That's not merit, that's just royal preference. Esther and Salome did one pleasing thing, one time. No points. No credit account. Just likability.
In the ancient world, you can earn favor by doing one good thing, or by doing many things OR just because somebody likes you. However, to earn ROYAL FAVOR you generally have to be "in" to begin with. That's why New Testament "Grace" is so amazing. It's not something we could never have earned. It's something we could never have gotten, at all, anyway. Period. Peons don't get the chance to present themselves before Kings, much less manage to prove themselves royally likable.
Re-read Luke and Paul with this understanding - substitute FAVOR for "grace". The difference is often astounding (not to mention inspiring). Instead of a conceptual principle God himself must adhere to, you get something that is inherently relational, something saturated by the personal pleasure of God. God's FAVOR is now upon believers, sometimes also upon our endeavors. Not that we pleased Him ourselves, of course. Christ did. On which point, now we can go back to John.
Wait. First let's do one other thing. For a functional understanding, let's define the Law, all the Hebrew laws, God's commandments, as things that God wanted people to do. If people fulfill God's commands, that would please Him, would it not? Therefore, practically speaking, we may define the Law as the Hebrew way of earning God's FAVOR. [or at least trying to]
Okay. Now, re-read John 1:14-17 with FAVOR instead of "grace". Instead of the oft quoted caricature of "grace" and "law" as polar opposites, we see John summing up all of History, from pre-existence through Israel's heritage until Christ. There may still be a subtext of conflict, if some of John's readers were still too tightly bound to the Law, but in John's actual piece, Moses and Jesus are presented as a progressive dynamic of God's contract with Man.
God gave Moses the Law. [Understood: Christ fulfilled the Law, which pleased God. Therefore, God's] FAVOR came through Jesus Christ.
Moses ==> Law ==> Christ ==> Charis
I don't know if this is a totally new reading of John, but I do think it blows away the theological insertion of "unmerited". If my reading between the lines here is correct, then God's favor was hardly unmerited. Jesus earned it.