agnostic
Used in philosophical or religious contexts to describe a stance that the existence of God or ultimate reality is unknowable. Often appears as 不可知論 (agnosticism).
He takes an agnostic position.
She is agnostic about the beginning of the universe.
Compound of 不可知 (unknowable) + 的 (-like, -ic). 不可知 is from 不 (not) + 可知 (knowable).