"Is the implication that there is some inconsistency between left wing politics and religion?"

For some people there is...for some there isn't. It all depends on whom you talk to about it. The Left is not, by definition, a movement espoused only by atheists, although some leftists will swear up and down that it is. That's their presumption. It says something about them, not about socialism. Some of the most inspired socialists in history have also been people with strong spiritual beliefs, and Jesus' teachings, to me, sound a lot like radical socialism. (this in spite of the fact that rabid anti-socialists can be found among conservative Christians...big deal...doesn't mean a thing as far as I'm concerned. Anyone, no matter what their political beliefs, may or may not be inclined to belong to a religion or to have spiritual beliefs.)