And if the biblical deity does exist... then he's evil and not worthy of worship.
Not only the biblical deity, but even "the source" or what have you. Many believers of all stripes, be it "New Age", Christian, Muslim, Jewish .. etc, at the root of their beliefs, is a "Creator" or God that is "good".
What in reality, in our experience, makes this such a common belief? We're just optimists by nature perhaps.