Um, because we are not God. Only God is God. Prophecies have been around since the beginning and have been spot on to the detail. SOMEONE has to know the future. It's common sense. Free will is undisturbed by foreknowledge of certain aspects of the future. That's why more than anything, cataclysms are foretold and not just any old thing. Lord willing, read Romans Ch8-11 (KJV). Even the chosen elect can lose salvation and even the worst of sinners can be saved. A clock maker and a watch.

Here's an example. For over two years, I have known that Obama will anounce that the Pacific Ring of Fire will go off, that the biggest city in the world (evil wise) will be destroyed, the false image of Jesus will appear via blue beam, that "aliens" will reveal themselves and that the military will kill their own people, with little to no remorse. Holla at me Lord willing, when these events go down.