To find out if the Bible is testable, it is first necessary to determine what the Bible is. The Bible is not just a collection of religious stories, nor is it a collection of myths. It is not even history mixed with myths. The Bible is actually the most reliable ancient document known. Likewise, it is also without question the most well preserved ancient document known.
Even if the Bible were itself inherently untestable (which it is not), creation scientists have produced scientifically testable theories based on it. Therefore the testability of the Bible does not affect the testability of scientific creation theories. As a result the claim that Creation Science is not science because the Bible is untestable is shown to be false on the face of it.
Having said that, the Bible gives a detailed historical account of Earth's history, of ancient Israel as well as of nations that interacted with Israel; it goes on to record the life, death and resurrection of Jesus Christ and of the early church, the beginning of Christianity. The Bible is at least as testable as any other account of history; it can be easily tested by archaeology, other corroborating documents and the like. However historical accounts are always difficult to test because the past can not be directly observed; any difficulty in testing the Bible is no worse than the difficulty of testing any other view of history.
So while the Bible may be difficult to test in some areas, these difficulties are actually quite common to historical research in general. The Bible provides truth in all it speaks on.
The historical data presented within the Bible have been and are consistently proved factually accurate through archaeology, what I like to call physical history. The critics always rise up and are always silenced when archeological science catches up with what the Bible has spoken on thousands of years before.