Why don't Christians understand?

Why don't they understand the difference between evidence and claims? Christians are constantly referencing the Bible as they try to buttress their claims. The Bible isn't evidence. The Bible is the claim. Why can't they understand this?
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And for people whining, as the usually do, about this question being directed at Christians, I also include Jews, Muslims, etc. But since this country is the vast majority Christian and Christians are the ones that are constantly saying these things to me. That's why my question was worded that way. But anyone else of any other religion is free to answer also.
Why don't Christians understand?
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