That's not why we don't believe. Here's a *short*Link Removed list of some reasons not to believe:
Many other vastly different religions exist: All proclaiming their truth [ie one true God].
Faith is rewarded to the same degree as disbelief; Prayer is a 50/50 shot.
God can't be proven.
The God of the Bible can be disproven; If he were really the author of the Bible, it would be much less full of atrocities, contradictions, plagiarisms and absurdities. The only real knowledge we have on the subject comes either from numinous, unverifiable personal experiences or ancient books of mythology which can be proven to be nonsense.
Religion, by nature, is deluding: Insubstantiality; When you ask God to do something and he does not, it is easy enough to come up with any excuse for him, and since he doesn't really exist any excuse fits neatly.
Science is better: It does have a method for obtaining answers, whereas religion simply claims answers.
The origins of all religions are clear: God was made in manās image.
He was a creation of humanity from when we couldn't figure out any better explanation for the difficult questions of existence.
Religion is destructive: It separates, divides and isolates. Religion creates rifts and divisions in the world. It causes backwards-thinking and halts medical, scientific, and societal progress. It encourages people to be content rather than try to better themselves, and to trust in an invisible friend rather than strive to succeed.
Evil exists in the world: Epicurus; āIs God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God?ā
"Free will" Is it the free will of all those precious children who die of leukemia, or AIDS, or SIDS, or who are born into the world handicapped or diseased at no fault of their own?
We are told anyone not accepting Jesus into their hearts are to suffer forever in a lake of fire. What of those who have never heard of Christianity. What of those who tried to believe and failed?
I can only believe what's known to be true.