What does the seeming lack of clarity in the book of James say about God?
The clarity or perspicuity of Scripture—which is a doctrine that I think we should hold to—doesn't mean there are no perplexing things. As Peter says of Paul, he has written things, "some of which are hard to understand" (2 Peter 3:16). And then he adds that people "twist them to their own destruction." Thus he says there is something hard to understand, but then he blames the twisters.
The difficulty of understanding the Scriptures is not a difficulty that, if we were patient, humble, meek, prayerful and studious, we would abuse and misuse. Nonetheless, they are still hard. Perspicuity doesn't mean nothing is perplexing or hard. It just means that you don't have to twist it in a way that it's going to hurt people.
So when you come to James and Paul you're going to find things that are perplexing. Now I could name other things in James besides chapter 2 on justification (which is what this question is about). For example, when he says, "Let not many of you become teachers...because we all make many mistakes" (James 3:1-2), I say, "We"? Did you mean "we"? That's a problem! You're the authorized biblical spokesman, and you're saying that you make many mistakes!
OK, we got problems. I got problems all over the Bible! I read the Bible every day, and every day I see a problem! So the question is not so much, "Would Paul have told James, 'Get your act together! You're not a good communicator'?" Rather, the question would be, "Is James written in a way that, though hard or perplexing (as Paul is hard and perplexing in places), it is designed by God not to be too hard, in order to protect it from having the false teachers do to it what they did in 2 Peter when Peter said that they twist it to their own destruction?"
I don't think Paul would have said to James, "Don't write that book," if he had known all of the factors in James' situation that led him to write the book.
Here's an analogy. I've often wondered, If somebody walked through my house, could they find anything that would indict me? Could they find pictures or financial records or internet history that could indict me? And my answer—I hope this is true—is that they could not, as long as they knew everything that I know about why those things are there (which they probably wouldn't, which means they would indict me). But they don't know why that check was written. They don't know the facts. They don't know why I went to that site about prostate cancer that had that information.
And so if we knew what James was dealing with, we would approve. Paul would approve. He is God's inspired spokesman to write it.
Now we're confronted—with knowing all that is in the Bible—with how to read it. That's the more urgent question for us.