Atheism v. Religion
If your measuring stick is pure reason, then there is no contest. Atheism wins, because it relies on a single claim: there is none higher than the voice of reason. On this view, the notion of a supernatural God cannot be admitted into our belief system, because such a notion is beyond human comprehension and analysis. The idea of such a God embodies contradiction, and is therefore said to rest on faith, not reason.
As complex beings in a complex world, however, pure reason is not our only measuring stick. We might, for example, consider the social and psychological benefits of religious traditions and rituals. In that case, pure reason is not enough to decide the value of religious belief; we must factor in other considerations.
In fact, much has been done to study the social and psychological causes and consequences of religion. Books like Daniel C. Dennett's "Breaking The Spell: Religion as a Natural Phenomenon" have spoken critically of religions, but have also tried to treat the subject honestly and with a fair mind, without drawing premature conclusions about the possible benefits (or problems) afforded by the world's religions.
Of course, with this approach, the decision is not about whether or not God exists, but whether or not the world is better off believing that God exists. For a large number of theists, this attitude contradicts their very understanding of religion and religious belief. They do not want their beliefs to be subject to rational or scientific analysis. Nothing comes before the word of God, the word of their pastors, and the feeling deep in their hearts that science and reason cannot give us all the answers, and that they must trust in faith.
Thus, the debate between atheism and religious belief is framed by pitting reason and science against pure faith. This is not a debate that theists can win, however. For, such a debate fully embraces irrationality and contradiction. It negates the very possibility of a logical chain of reasoning.
Atheist belief is not based on a set of tenets which must be maintained in the face of contrary evidence or logic. On the contrary, atheist belief is based on the striving for stronger and better beliefs, and new evidence is always allowed. Reason is always admitted and celebrated.
Historically speaking, science and reason have not been antithetical to the development of religious institutions. As the sciences of psychology and sociology teach us, religions have not developed through pure faith alone. They are practical and economical organizations which have served a wide variety of human needs, and they have grown and developed pragmatically, evolving along with the rest of humanity.
We cannot deny the roles reason and science have played throughout the history of religious institutions, just as we cannot deny the crucial roles they play in every aspect of our lives. We therefore cannot deny reason and science when deciding the value of religious belief.
Ultimately, we might find some reason to value and celebrate religious beliefs, be they Christian, Jewish, Islamic or what have you. However, we cannot do so by negating reason and science. We cannot decide this debate on faith. When it comes to a choice between science/reason and faith, faith must lose.
If this means that atheists are given an advantage in this debate, so be it. It is the same advantage given to every human being born with a working brain: it is the advantage of rational thinking. The alternative would be to deny the human species what is rightfully ours, the ability to seek wisdom.

