Reposting of my comment on a friend’s blog:
I think my main problem with this, and I admit it’s halfway to being nitpicking, is that the term “Religion” is used as though the millions-or-tens-of-millions of religious doctrines and beliefs were all the same. Absolutely wrong — the only thing which they have in common is that, as far as I know, none of them can prove the existence of their god(s)/spirits/what-have-you. The behaviors (and?) morality which individual religions prescribe vary almost as greatly as the number of villages and neighborhoods in the world.
I think it’s possible to evaluate small-body religions on the behaviors which their practitioners exhibit. Do they treat their neighbors well? Strangers? The poor, the sick, the young, the old? Do they encourage their believers to engage with the world, to learn, to think clearly? What do they consider to be sinful/destructive/unacceptable/wrong behavior and what consequences do they prescribe for religious misbehavior? Civil/secular misbehavior? Do they believe in conversion by the sword, by the word, by good example, not at all (e.g. Shaking Quakers aka “Shakers”)?
However, when you’re trying to evaluate larger groups in terms of their religious practice, it gets a lot harder — for one thing, you automatically fold a lot more diversity into a single group, sometimes including intolerant and/or murderous extremists who claim that religion justifies their will to murder/harm/dominate others.
The whole issue of diverse groups (e.g. Sunni, Shia, Sufi, Druze, and whatever groups Indonesia has, and call them all “Muslim”) becomes whether there is, in fact, a single normative behavior set, or whether it’s all multi-modal and controlled by factors other than whatever the common written doctrine is (assuming there is one).