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.
不可知論 is the noun 'agnosticism', while 不可知的 is the adjectival form 'agnostic'.
無神論 (atheism) asserts that there is no God, whereas 不可知的 (agnostic) claims that the existence of God is unknowable.
Compound of 不可知 (unknowable) + 的 (-like, -ic). 不可知 is from 不 (not) + 可知 (knowable).