According to the comparative mythologist, Joseph Campbell, mythology arose as the use of symbolism to fit consciousness to its physical and social environments through different stages of life.
Theism arose as the belief in mythic symbology as fact.
Atheism arose as the disbelief in mythic symbology as fact.
Agnosticism arose as abstaining from the choice of belief or disbelief in mythic symbology as fact.
With symbology misconstrued as fact, to be believed or disbelieved, the meaning of the symbology is ignored and lost. See Making Sense Of Religion.