A questions about god and religion.

Whenever we talk of a ultimate truth,that truth should live for all eternity.Even if that truth is erased from mind of all existence at once,it should come back again because an absolute truth should remain even if it is erased from all minds but why is it that when I think of god and religion it do not seem a ultimate truth cause if for once it is erased from all minds,it will never came back and if any person talks of it we won't think of the.selves as a saint but a manipulator or psycho.