Pashuteh Yid:
The Rambam clearly states that is one does not believe in any certain principles, he/she does not have a share in gan eden. One could be the biggest mensch in town, but if he doesn’t believe in tichiyas hameisim it’s not getting him anywhere. If the be all and end all of the Torah was just menschlichkeit, one would imagine that anybody and everybody who practiced menschlichkeit would get some gan eden for their efforts.
Josh31:
Not entirely sure what you’re getting at. However, Judaism is based first and foremost on observance of the Torah, and only after that “upon shared national experiences”.