Why believe Yahweh is the most perfect being?

Randal is reading a Calvin and Hobbes book in the middle of a bustling, bohemian coffee shop. Suddenly ConverseAtheist walks up and taps him impatiently on the shoulder. Randal looks up and ConverseAtheist begins to speak:

"You requested my patience regarding your case against Zeus... that was a couple of weeks ago." Randal nods as ConveseAtheist continues: "Last I remember, you thought that it was fair enough that I was an atheist w/ respect to Yahweh being the same as a perfect creator as you were an atheist w/ respect to Zeus being the same as a perfect creator. And that you were agnostics about whether Zeus was a lesser spirit being."

Randal takes a slurp of his coffee and gestures for ConverseAtheist to continue:

"Were you going to present a case that lends credibility to Yahweh being a perfect creator rather than a lesser spirit being like Zeus?"

With that Randal glances at his laptop where the internet is currently open to his latest blog post: "Does the Trinity make sense (and does it matter)?"

In the awkwardness of the moment ConverseAtheist hastily adds: "Sorry for not being on topic for this post, I was just hoping I hadn't missed the train on this previous discussion."

Randal gulps the last of his coffee and smiles. "Your request is most reasonable and most welcome." 

And with that a hush falls over the coffee shop, and everyone turns to watch the unfolding scene. Somewhere in the background a sitar begins to play and incense wafts on the air as Randal speaks:

"First, let's consider the challenge before us. There are two types of defeater."

Suddenly a young college student from a nearby table cuts in: "What's a defeater?"

Randal turns to face him. "A defeater is simply a belief which serves as evidence against another belief. And as I said there are two types: undercutting and rebutting. An undercutting defeater is a belief that undercuts your grounds for accepting the other belief."

The young college student looks confused. "Come again?"

Randal continues: "An undercutting defeater does not provide direct evidence that a belief is not true, but it does undermine the evidence you have to think it is true. As a result, without further evidence you lack grounds to accept the original belief."

A dreadlocked mathematician in the corner pipes up: "How about an example doc?"

Randal nods. "Imagine that you are supposed to meet Juan at this coffee shop. Since you've never met Juan before and you don''t know what he looks like, he tells you that he'll be wearing a black 'Democracy Now!' T-shirt. Sure enough, as you come into the store you see a man sitting in the window wearing a 'Democracy Now!' T-shirt. That provides good prima facie evidence that this is Juan, and thus would justify you in believing 'The man in the window is Juan.' But as you open up the door you now see that there are ten or twelve guys in the coffee shop, and every one of them is wearing a Democracy Now! T-shirt. That new discovery does not provide direct evidence against the belief that the man in the window is Juan, but it does undercut your initial grounds to believe he is. Thus, if you are to continue believing that he is Juan, you will need some additional evidence."

The college student smiles. "I get it. What about rebutting defeaters?"

"A rebutting defeater provides direct evidence against the belief. So let's say you're now in the coffee shop and you walk up to the man in the window and ask him: 'Are you Juan?' And he replies: 'No, my name is Josef.' That testimony now provides an additional rebutting defeater to your original belief."

Randal concludes. "And so you can undermine justification in a belief or you can directly rebut it. Clearly the latter is stronger." With that he turns to ConverseAtheist. "Now that analogy is much like my present situation. I believe there is a most perfect being and I draw the initial conclusion that Yahweh, the being revealed in the Bible, is that being. My challenge is that I seem to encounter both undercutting and rebutting defeaters to that claim."

The mathematician cuts in. "So what are those defeaters? And what's your response?"

Randal looks over to him. "I'll get to that in a minute. But first I need another cup of coffee."