I'll have a go, Rebel8,
Terry's post, as I understood it, ridiculed the alleged source of the book, without addressing the content. It also asserted that claiming the source was Jesus, was intended to use Jesus as an authority.
I've read some but not all of ACIM, and, like others here, enjoy exploring the different ideas it presents. No reason why I need an "authority" to do that, or a basis in fact either.
IMO, these concepts, and your perception of "cultish", don't apply here. No-one will shun me or regard me as a living corpse if I accept some, all or none of it. Or whether or not I change my mind later.
And just for context, I get a lot from Terry's well thought out posts. Also I work as an analyst, and my work deliverables are entirely based on facts and probabilities.
ACIM etc., occupies a different part of my alleged brain .