I used to say that the letter of James shouldn't be in Scripture, because his doctrine of Justification by Faith and Works was incompatible with Paul's doctrine of Justification by Faith alone.
I'm sorry I said this, because I maligned God's Word, and I told many people this error.
I now see that James is talking about Justification before man (the context is "show me your faith... and I will show you mine."). Paul is talking about Justification before God ("...what will you have to say at the Judgment Throne?" from "Trust in Jesus" by Third Day is playing as I write this). "If, in fact, Abraham was justified by works, he had something to boast about—but not before God." (Rom. 4:2). Totally different concepts.
Thanks to Dr. James White for clarifying this. Also, this article is helpful, though I came to my senses before finding it: http://www.presenttruthmag.com/archive/II/2-9.htm