Christians must take parts of the old Testemant to be completely literal without exception

So often when I speak with Christians they tell me that they do not believe the Bible to be 100% literal.

I can certainly understand this--how can anyone really believe in a talking snake? But there is one story in particular that every Christian MUST take to be completely true. This story is the tale of Moses and the Ten Commandments.

Christianity hinges on this story. To be a Christian, one must believe that Moses went off on his own, climbed mount Sinai, was greeted by Yahweh in the form of a burning bush, and received the tablets with the 10 commandments written on them. Without this story, there are no laws for humans to break and sin against god. Without these sins there was nothing for Jesus to save humanity from. Thus, this story is the cornerstone to Christianity.

Now I ask this question: If you believe this story, you believe that Moses existed and was in direct contact with Yahweh. Therefore, there can be no reason to doubt any other account of Moses written in the bible. And if those stories are true, how can anyone doubt the other tales within the bible?

These are questions that every person who calls themselves a Christian should ask.