One fundamental precept of rational thought is that arguments speak for themselves. Claims exist independently of their speakers. You can't rebut an argument by suggesting that the person who made the argument has "chosen sides" or has any other characteristic whatsoever. You have to address the content of the argument itself. The human is irrelevant.
Everyone should read Greenwald's article. He makes a good case.
I can't imagine that the people downvoting this comment would do so if they saw it in a politically neutral context. It's completely uncontroversial in what it said: arguments can be evaluated without regard to who is making them. This is middle-school citizenship class stuff.
As long as it's me that gets to determine what is "biased" and what is not, sign me up. I also have thoughts about what is a "real" religion and what isn't, if you need more help.