“What the Reformers held was that a believer is entirely rational, entirely within his epistemic rights, in starting with belief in God, in accepting it as basic, and in taking it as a premise for argument to other conclusions.”
To be blunt, uniformity is an outright and blatant contradiction of the theory of an open universe. An open universe frankly cannot provide the necessary preconditions to make human experience intelligible. The metaphysical starting point for the non-Christian worldview, namely an open universe brought about by pure chance rules out any possibility for genuine knowledge before the conversation can even begin. Hence, the nature of epistemology is such that it must be constructed upon something other than that which the non-Christian worldview builds it, finite, autonomous human reason.