I think the main reason I consider the Manifest Path a religion is that, to me, it takes the established facts of the BM world and runs with them. SMA does not trump the facts of the BM world to me.
Religion is not based on unequivocal facts, and hard scientific evidence. It is based on faith and belief.
Our characters live in a world where giant monsters and armies of the undead routinely walk the earth and try actively to destroy us. They live in a world where the gates of Hell (or a reasonable simulacrum) open up on a semi-regular basis, and fire-breathing flying horrors that roast entire villages in an evening twist the very fabric of reality to destroy human resistance. They live in a world where there are entities that display power on the level of gods...And all of those entities want to consume humans, including the Light which demanded blood sacrifices.
That is incorrect. I think you can find a rather large portion of the character in BattleMaster who do not hold that all supernatural powers want to destroy/consume humanity. Your character may believe this to be true, but I'd imagine he is in a *very* small minority.
And not once has any entity manifested itself as humanity's protector, leaving aside the Light which can have serious issue taken with it.
Again, incorrect. The Blood Stars have intervened on behalf of Sanguis Astroism many times. In fact, the aid of the Maddening Star was crucial in the most recent assault on Valkyrja. At least, so far as quite a bit of Sanguis Astroism is concerned. Just ask the Holy Prophet. He was there and declared that it was so. And the Maddening Star was bright and superior in the sky, giving proof for all to see. Again, so far as the worshipers of the Blood Stars are concerned. In fact, some even believe that the current war was instigated by the Stars themselves to unify the church of Sanguis Astroism, and draw it together to prevent it from fracturing.
But again, these are all matters of Faith, and not scientific proof. Our characters believe them to be true.
...and can point to what has happened on Beluaterra as proof positive that the gods are no longer protecting us as they once did.
More likely, they followed false gods. If they believed in the
true gods then obviously none of that would have happened to them. Poor, misguided heathens...
How would anything like the Christian church continue to function in Battlemaster when there is proof positive that God is not protecting us from the unimaginable horrors?
How do the Christian churches continue to function today without this proof? How did the Jewish faith survive during the holocaust? Or, pick any other religion and any incredibly destructive natural disaster. Are not all of these things proof positive that God doesn't give a damn about humans? I mean, if He was protecting us, then how would tragedies like the Holocaust have been allowed to happen? Or the World Trade Center attacks? Etc., etc., etc. ...