“Adulteresses!”
Say what you like about James, he knew how to get a reader’s attention.
And people have said a fair bit about James over the years, not least Martin Luther, who famously called his letter an “epistle of straw”. There’s no getting around the fact that there are aspects to the missive that are theologically difficult, a tone about it that is markedly different from Paul, Peter, John and even Jude, and a strong Jewish flavor to it that can confuse Christian readers.