James does not start a new discussion, but continues his discussion of doing all that God's law requires. Such is described as perfect faith, or faith that is complete. Faith is made complete, or perfect, when it is accompanied by the works of obedience ordained by God. We cannot decide to only do part of what God says - such is incomplete faith. The faith that is alive, and thus pleasing to God in the life of a Christian is a faith that works, or obeys God in all things.