"At first glance James seems to contradict Paul. He does not. The key is to understand the difference between works as Paul defined them and works as James defined them. For the purpose of my argument I will refer to Paul's term as "works" and James' term as "work." We are not to do works, but we are to work."
Johnson goes on to write this:
"Works" [as Paul defined them] are tasks undertaken for the purpose of raising our own stature. "Work" [as James defines them] is undertaken to raise God's stature. …Works are useless at procuring salvation. Work is an absolutely essential part of procuring salvation. We will never get to the promised land by doing works, but we will also never get to the Promised Land if we refuse to work."
So, Johnson is trying to convince the reader that they must do "work" (as James defines it) in order to get to Heaven, but he says it must not be work for the purpose of raising our own stature. That sort of work, he says, will not get us into Heaven. We must "work" only for the purpose of raising God's stature. If we do work for the purpose of raising our own stature, then we are doing "works" by Paul's definition, and this sort of work is useless at procuring salvation.
Question: Is it not true that my own stature is raised when I enter Heaven?
If you tell me that I can't get into Heaven unless I work (even if for the purpose of raising God's stature) and I become convinced that such works are necessary for entrance into Heaven, then guess what? Whatever I do will be for the purpose of raising my own stature. (i.e. enter Heaven) In other words, if I do any kind of work with the idea that without that work I can't go to Heaven, then the motivation behind that work becomes that of raising my own stature: getting myself into Heaven!
The only way to ensure that the work we do as Christians is properly motivated is to completely and totally disconnect it from entry into Heaven. We must regard our work as contributing absolutely nothing toward our entrance to Heaven. We must understand that we will go to Heaven with or without the work. We must understand that we are, for all practical purposes, already in Heaven.
This is why Paul says that salvation is not of works. The only way to work out of the motivation that Don Johnson suggests (that of raising God's stature) is to be convinced that doing that work does nothing to get you into Heaven. Otherwise, the work becomes for the purpose of getting yourself into Heaven, and that is ultimately a motivation of raising your own stature.