A passage caught my eye in this book on Luther: he was the first Christian "to devise an entire religion accommodated to his personal failings." Prior to him, it was for man to do the accommodating, not vice versa. This has redounded to "a plague of designer religions" numbering some 33,000.
Does every one of these constitute "bad religion"? I don't think so. Or, at the very least, there is a spectrum of wrongness. Nevertheless, I would guess that the vast majority of these -- from Jeremiah Wright to Fred Phelps -- are more human than divine, and that the choice of this or that version often comes down to the accommodation of personal failure, or inability to conform to the unvarnished doctrine.
Let's take an obvious example: the gay activist who nevertheless wants to call himself "Christian" will find that his failing is accommodated by Episcopalianism but not Catholicism (at least prior to Francis). Likewise the abortion advocate. At the far end of wrongness, heresy is elevated to sacred doctrine.
But still: how do we distinguish between good and bad religion, and is it even up to us to make this distinction? Here again, Luther's entire argument -- sola fide -- is that it is strictly impossible for man to make such a distinction. Rather, he is totally depraved, and pretending he isn't totally depraved is the worst form of depravity. All he can do is assent to the doctrine, so it is a matter of will, not intellect.
Eh, I don't like that idea. Yes, we must surely guard against intellectual pride and arrogance, but still. Doesn't Luther take it a bit far? Indeed, "the affirmation of the will over reason" might be thought of as a "renewed manifestation of the pride that characterizes Original Sin: the desire that the order of Creation bend itself to human will."
In other words, trying to make religion conform to the will is no better than making it conform to the intellect; both constitute manmade religiosity.
More to the point, just as we cannot separate thought from perception, we can only artificially sever intellect from will. Luther absolutely rejects free will, and with no freedom there can be no truth in any event. Frankly, his whole program is hopelessly incoherent and contradictory, and he spent much of his life trying to explain or paper over the inconsistencies and implications he didn't like.
It is also probably accurate to say that a majority of Protestants don't agree with the founder of Protestantism anyway, and don't really know (or care) what he believed. It is as if they spontaneously reject certain teachings that would constitute bad religion, such as the intrinsic heresy of predestination (AKA denial of free will).
So, right there we've identified a key meta-theological principle of Good Religion: recognition of free will in man. Any religion -- including of course secular religions -- that denies this freedom is a Bad Religion.
Of note, one of Islam's non-negotiable six articles of faith is predestination. Is there a way to purify such a doctrine of its badness and render it good? I think so, if it is deployed as a "skillful means" to cultivate such attitudes as peace, surrender, humility, and recognition of God's greatness. Still, this doesn't make it metaphysically true, just useful.
Running out of time, but I wonder what other aspects of Good Religion we could all agree upon, thus giving us a way to recognize bad religion?