Once new knowledge and spiritual truth get into our heads, however it is that it happens, reason is now available to do its work. Even though reason works well within both the spiritual and physical dimensions in the confines of the same wordview and knowledge set, I believe it cannot work well across different knowledge sets and worldviews. Reason is inexplicably tied to it’s bearer’s presuppositions and set of knowledge – removed from them it has no context and therefore no effectiveness, like a hammer without a person.
It seems that for people of differing worldviews to criticize each others beliefs using reason, they are jumping the gun. They must instead start by examining each other’s worldviews that reasonably lead to their beliefs before progressing to the beliefs themselves. Both parties are to a lesser or greater degree reasonable according to their presuppositional framework, so the frameworks are the only things that people of opposing worldview can argue about. For reason to work across frameworks, the parts of the frameworks that are agreed upon must be the knowledge that it works off of. In the case of the deist and the atheist, the common denominator would be a belief that the existence of empirical evidence is required for something to be true.
The only way to argue about each other’s beliefs would be to both compromise and agree on a new worldview, and then proceed (not in this world :)), or more likely, to borrow each other’s framework and encourage them to use more reason and logic where their is some internal inconsistency, but all within the confines of each other’s respective frameworks. This works to an interesting advantage – people of differing worldviews can actually use reason to help strengthen each other’s internal consistency of beliefs. This is especially good because they might have some good new knowledge to lend to the discussion. This new knowledge will most often be fit into the worldview and reconciled with the rest of the beliefs rather than changing the worldview. Worldviews, in my experience, are not changed quickly, but need a LOT of repeatable, observable evidence, either from the spiritual or physical universe to be changed. Even though reason is responsible, I don’t think it is enough. Usually there are other things behind big mental shifts in our minds.
Arguing a worldview using reason is quick and rarely profitable. An atheist can argue that God does not exist, but it seems they can only do so by poking holes in the inconsistent beliefs and not the worldview (and by doing so jumps the gun logically). The burden of proof does not rest on them anyway, nor should it. The burden of proof for the existence of God would most likely be the job of the deist. So the rational argument comes down to the deist on the spot to prove the existence of God while the atheist listens and refutes the proof on the basis of empirical evidence, probably limited to the physical dimension because sensing and testing truth in the spiritual dimension is not well understood by the average atheist or deist. However, as a deist, and more specifically as a Christian, I believe it is not my job to convince logically and reasonably the existence of God. I’ll let God himself be the primary owner of the burden of proof for His own existence. My job, if any, is to help people see the reality of the spiritual life, and to encourage others who already believe in its existence to press on as they navigate through it with reason at their side. I’m hoping they can encourage me too.