Actually this is very old. The Christian Gnostics of a certain stripe suggested that the God we know in Christianity is not the God of the Universe, but only the Demiurge of some lower order of reality, and therefore the only form of eternal life that can be offered by such a God is really a form of limitation and therefore a kind of eternal suffering.
Their argument is basically the argument from evil. Only a God that was flawed or insane would have created material reality, which is at best a confusing delusion, and at worst a trap. So any higher reality offered by such a God probably isn't exactly what He thinks it is.
They aspired to look beyond Him to a higher order of the Real Universe ruled by a more ultimate God sometimes known as the Monad.
(Sometimes they limit this only to all forms of Christianity continuous with Judaism, since they identify the Demiurge with Yahweh in particular, and propose there are messages hidden in the words of Jesus that point to the higher reality, sometimes through the mystery of the Trinity, etc. This explains how these variants remained Christian, preserving Jesus as a Savior figure, and did not become variants of 'Satanism' like others (If God is evil, and Satan is real, then he is your friend.) Since every form of the tradition was ultimately suppressed as a heresy, it is hard to know what parts were actually commonplace, and which ones just happen to be expressed in the remaining traces nobody destroyed.)
More recently we have the Evil God Challenge. The challenge to prove that the philosophical version of God is not just as likely to be ultimately evil (and sometimes therefore also the ultimate liar) as He is to be ultimately good in any way. If he is just as likely, or more likely, to be evil, then all the continuity between actual religious beliefs and most of the theology that borrows from Plato and Aristotle is broken.