Yes you can say that. Why would we be better off without saying these things?

There’s nothing wrong with speaking out when we see people saying things we believe to be false and it’s unreasonable to expect everyone to hedge every single thing they say simply because, well, we don’t really know anything.

I know there’s no omnipotent being who cares so much about the minutiae of our lives yet allows terrible things to happen. I know the bible was written by people who never experienced the magical things written about. The onus of proof is on the one making the extraordinary claim and religion is firmly on the side of the extraordinary.

Focusing on the impossibility of knowing is just skirting the issue of the impossibility of the claims.