Science v. Christianity???

Why is it that so many Christians and scientists think that its an either or proposition. Either you can believe science or you can believe the Bible. I find it amazing that so many otherwise intelligent people believe that they are mutually exclusive of one another. Perhaps we are just born Kantian. However, I think that this is a false suggestion. Christianity and science are complimentary of one another and are (in their purest forms) out to answer different questions to the same puzzle. Neil Turok in a piece this week out of WIRED made a statement that I have been screaming for years. Science is in the business of answering how and religion (Christianity) is in the business of answering why. So very true. Yet each side continues to make claims to answer the questions that their manuals are not equipped to handle. The Bible exists to tell us about the triune God and that He made the Heavens and the Earth good, we screwed it up, but He did not leave us to perish but sent His perfect Son Jesus to redeem us if we would but believe. Science on the other hand "can" tell us how these Heavens and Earth were created, but can absolutely add nothing to the conversation of their purpose. Thus science and Christianity together offer a fuller picture of the same puzzle. Christianity gives us purpose, science tells us how it plays out temporally. Thus we should be working together and not against one another in our constant pursuit of the the truth.