I dont really see how the race, religion and status are important, perhaps they correlate with privilege and therefore their grievance can appear less legitimate to some people but that's how it is.
There is exactly an inverse perspective which suggests that non-white, irreligious, underclasses have no legitimate grievance because they do not have the same life experiences or troubles as the middle classes.
By itself I dont think the constituency is as important as their ideology or drive to realise it, I think there's a great deal of similarity between ideological capitalism and its anathema Marxism, in my experience they appeal to similar personalities for similar reasons.
As far as associations between capitalism and Christianity go, that's a complete mistake, the capitalist idea of man as rational, avaratious calculator is as inaccurate or one dimensional as Borg like communism. Smith supposed not that man was naturally greedy but that hopefully price mechanism markets would harness the worst for the better, not that people were necessarily so, now that its in full effect people have to be that way to succeed. Effectively capitalism has become normative, instead of resting upon pre-existing norms.
There are also as many, if not a lot, lot more, utopian ideas and fantasies about perfectability of both individuals and prices or allocative efficiency within capitalism as socialism. I can name three right away, personal responsiblity equals success, parsimony is rewarded, there is a trickle down effect/a rising tide raises all boats big and small.
Likewise I'd question whether or not Christianity and the bible are actually averse to perfectability, the Irish monastaries who preserved Christianity through the dark ages wouldnt have understood that, they had an optimistic creed based upon the idea that "Ye Shall Be Gods". I'm not sure that the present day Scrooged, Puritanical, Calvinistic Christianity could have survived the Dark Ages.