James is not writing about how to become a Christian, but rather how to act like one. Having all the correct beliefs about God will hardly suffice: even demons believe in God. Real, life-giving faith should produce motion, and James minces no words in describing the specific spiritual actions expected of Christians.
Christian thinkers, notably Martin Luther, have struggled to reconcile the message of James with that of Paul, who so firmly warned against slavish legalism. But Paul never belittled holy living. When he wrote to carousers, such as in his letters to the Corinthians, he railed against immorality as strongly as James.
Evidently, Jame’s readers were not even flirting with legalism. They lived at the other extreme, ignoring those laws God had clearly revealed. James had a simple remedy: “Do not merely listen to the Word…do what it says” (1:22).
(The Student Bible-NIV)