Should a person launch into a detailed and involved study of the entire Bible before deciding that atheism is more reasonable than Christianity (or any other sort of theism)? Some Christians seem to think so by the way they act - sometimes asking, for example, just how much an atheist has studied the Bible.
It's not that a key element of humanism isn't atheism (or agnosticism), it's that the negative and combative stance of humanism-as-atheism (or secularism) wins no friends and more enemies. A re-booted humanism would recognize ethics and naturalism as its core. It would be defined as a sociopolitical philosophy, both democratic and non-hierarchal, which is informed by scientific naturalism, and promotes individual freedom, economic and social equality, human cooperation and planetary peace.
Sometimes theists find it odd that atheists would have web sites explaining, discussing, and defending atheism. If atheism is not a philosophy or religion, what's the point? If atheists don't believe in God, why spend so much time discussing God? These theists are, I believe, misunderstanding the purpose and reason for atheist sites. The reason for this misunderstanding may lie in the fact that atheism and religion are completely separate categories, and as such cannot be directly contrasted.
Secularism is used in a restricted sense today, but it retains a philosophical aspect in political and social situations. Secularism has always carried a strong connotation of the desire to establish an autonomous political and social sphere which is naturalistic and materialistic, as opposed to a religious realm where the supernatural and faith take precedence.
No religion is perfectly consistent when it comes to doctrines, ideas, and history. Every ideology, philosophy, and cultural tradition has inconsistencies and contradictions, so this shouldn't be surprising but other ideologies and traditions aren't alleged to be divinely created or divinely sanctioned systems for following the wishes of a god. The state of religion in the world today is more consistent with the premise that they are man-made institutions.
In most religions, gods are supposed to be the source of all morality. For most believers, their religion represents an institution for promoting an ideal model of morality. In reality, though, religions are responsible for widespread immorality and gods have characteristics or histories which make them worse than the most vile human serial killer. No one would tolerate such behavior on the part of a person, but when with a god it all becomes laudable even an example to follow.
A common characteristic of both theism and religion is their reliance on faith: belief in the existence of a god and in the truth of religious doctrines is neither founded upon nor defended by logic, reason, evidence, or science. Instead, people are supposed to have faith a position they wouldnt consciously adopt with just about any other issue. Faith, though, is an unreliable guide to reality or means for acquiring knowledge. Faith can be used to defend anything and everything equally.
Most religions say that life is much more than the flesh and matter we see around us. In addition, there is supposed to be some sort of spiritual or supernatural realm behind it all and that our "true selves" is spiritual, not material. All evidence, though, points to life being a purely natural phenomenon. All evidence indicates that who we really are our selves is material and dependent upon the workings of the brain. If this is so, religious and theistic doctrines are wrong.
Calling science a religion should be instantly recognized as an ideological attack rather than a neutral observation of facts. Sadly this is not the case, and it has become far too common for critics of modern, godless science to claim that it's inherently a religion, thus hoping to discredit scientific research when it contradicts genuine religious ideology. Examining the characteristics which define religions as distinct from other types of belief systems reveals how wrong such claims are.
Perhaps the most basic reason for not believing in any gods is the absence of good reasons for doing so. Since the burden of support lies first and foremost with those making the positive the claim the theistic, religious believers who say their god exists non-believers don't need reasons not to believe. They may help, but they aren't particularly necessary. Instead, what is required are reasons to believe.