From where I sit, most religions attempt to separate disciples from their god or goal.
Zen Buddhism is not in the separation business, though lord knows there are plenty of wise and uninformed people who try to accomplish exactly that.
But if Zen is not in the separation business, it might be inferred that it was therefore in the business of unification or oneness.
But this too is not the case: How could anyone in their right mind unify what was never separated in the first place?
Anyone wanting to know what Zen Buddhism might be will have to practice and find out. Nothing else works ....
Unless, of course, anyone would prefer to spend a lifetime in some religious dungeon with nothing better to do than separate and unify.