Every time I read James 1:2-4, I emphasize all. Some versions use the word pure. But, I prefer all because it, too, has a counterweight with the last word of the passage: nothing.
All (pas) and nothing (mēdeis, mēdemia, mēden) are included in each other’s Greek definitions. Consequently, there is a sense James is using juxtapose in his word choices as a means of proving one “it” leads to another. In this case, all of “it” leads to joy or “it” means nothing.