I know that the Jewish belief is "in the world to come" and that world is a physical reality. I don't know if it's also spiritual, but I would guess so.
However, everything that they believed has been clarified in Christ, whether they believe it or not, so I can't buy an Adamic rest for anyone unspiritual.
The meek will inherit the earth -- even that would imply spirituality, as both Moses and Christ are said to be meek
The operative point is that God is faithful. He keeps every single promise even if we Christians see no "need" for it.
I must head out now. See y'all later!