OW do we reconcile vs. 20-26 with Romans 4:1-9? Either works is part of the salvation equation, or it is not. If all we had was the book of Romans, we would say categorically that it is not. If all we had was James, we would have to conclude that it is. But, with both letters in hand we are forced to find a reasonable explanation for the divergent emphases.
The simplest and easiest answer here is to separate the horizontal from the vertical. That is to say that Paul was speaking of our justification in the eyes of God and James is referencing our justification in the eyes of those around us.
A second approach would be to simplify our definition of faith. In James 2:19 we read that even the devils "believe that there is one God... and [they even] tremble" before Him too. And yet they are not accepted or acceptable in the eyes of God. What's missing? James might say that their problem is that they have no works expressing any submission to the knowledge which they possess.
To put it bluntly James is teaching us that any brand of faith that does not surface through action is impotent and useless. We know that we must be saved by God's grace. We can never and could never live righteously enough to make ourselves acceptable in His sight (Hebrews 7:18-19). But genuine faith in God DOES manifest itself in us in ways that are perceivable (Romans 10:10). And really, there is no wiggle room on this matter.