"Concerning the gods I am unable to know either that they are or that they are not, or what their appearance is like. For many are the things that hinder knowledge: the obscurity of the matter and the shortness of human life." (Eusebius, Preparation of the Gospel 14.3.7 = 80B4)

Buddhism and Jainism are agnostic religions. Protagoras, Democritus, Hume, Emmanuel Kant, William James, Herbert Spencer, Albert Einstein were agnostic.

from an atheism website:
http://atheisme.free.fr/Atheisme/Agnosticism.htm