Agnosticism-Why we aren't all one

[de1337]

My question to all who are religious and not is short and blunt:

Why aren't you agnostic?

You can't prove God is real, you're just faithful.
You can't prove that God does NOT exist either, you're just doubtful.

Seems as if everyone should turn to Agnosticism, because you can't be sure of someone else's belief of the presence of an omnipotent being, nor can you be sure of someone else's belief in no supernatural force at all.