Religion, as an idea based purely on faith, has no place in the world of debate, an art based on logic and reason. logic, reason, and faith are wholly irreconcilable. Consider this definition obtained on dictionary.com:
faith-n
2. Belief that does not rest on logical proof or material evidence.
Therefore, one could go as far as to say that faith is the antithesis of reason. This begs the question: how is it even possible to debate religion? Answer: It's not.
Try this example,
Atheist: God is imaginary. Religion is ridiculous. Science can explain everything about the world that was once only capable by religion.
Theist: Exactly, there is no evidence per se to suggest a higher power, it is my faith in him that makes it real. There are so many things that can't be explained by science alone, and the creator is obviously responsible. Nature is perfect in so many ways that it is impossible not to suggest that there's something greater out there.
Atheist: Still, the bible is filled with contradictions, and God tends to act in ways that go against sense.
Theist: God is above human comprehension and logic. Since he is all-knowing, he acts in ways that would seem odd to us, but as we are not perfect beings, we can not comprehend his workings. All will be revealed in the end.
Atheist: That's a convenient argument
Theist: You ignore thousands and thousands of years of spiritualism and religion. It is obvious that the idea of some sort of higher power is deeply ingrained in humanity. How can you deny that?
Atheist/Theist: This could go on for hours. I'm right and you're wrong.
This is the result of 99.9 percent of debates on the subject. It typically ends with each side even more convinced that they are right and the other side is wrong. It also leads to a personal dislike of the other side, since these things always seem to boil down to vitriolic attacks. So, debating religion makes no progress, and is therefore, pointless.
On a personal note, while I consider myself agnostic, I can still see why one would choose to be an adherent to a faith. It promotes a strong sense of belonging. It also contributes to a sense of wholeness, since many deep, philosophical questions about life are addressed, mainly for the positive. I can definitely understand why one would want that in their life, I just feel like I don't need it to be happy.