The real emphasis of James 1:19-27 is the danger of self-deception. It is one thing for the Christian to be deceived by Satan, but if you deceive yourself, this is something far more serious.
The mark of a mature person, is someone who faces themself honestly, who knows themselves, and admits they needs help.
By contrast, the immature person thinks they are rich, self-sufficient, and have no need of anything.
James says that this all comes down to your relationship with God and the word of God.