Credible/Honest Apologetics?

[Belacqua]

The only first principles an atheist has to accept, is that: the outside world exists, and other minds exist, and we are not a brain in a vat being fed false information. But again, I don't think this is a faith based position, since I have evidence. 

I don't think any of those things are falsifiable. 

I mean, any evidence you have that you're NOT in the matrix could just be dropped in by the people who run the matrix. 

Like a lot of unfalsifiable things, there is no good reason to believe it. (I certainly don't believe we're in the matrix.) But that doesn't mean it's been falsified. 

Is it a first principle for you that you should believe things based on evidence? That seems like a reasonable first principle to me, but not one that could be proved with evidence. Because to accept the evidence, you'd first have to accept the principle. 

Is it a first principle that falsifiable claims are superior to non-falsifiable claims? Apparently not, since the three you list are not falsifiable. But science-type people often say this. So for them it may constitute a first principle. When they say there is no evidence for God, they are relying on a principle about what good evidence will look like: science-type falsifiable evidence, not personal unfalsifiable experience.

Is it a first principle that empirical evidence, interpreted in the light of current scientific theory, is better than revelation? This again seems unprovable and unfalsifiable, but lots of atheists hold to it. How could you falsify the idea that some revelation is true?

In addition, to be an atheist, you have to accept a number of other propositions:

1) religious claims have not been proven. 
2) the world is explicable, more or less, without positing God or other religious elements. 
3) that religious claims are "unevidenced stuff" that religious people add.

These propositions may be very reasonable, but they are certainly things that atheists believe. If "I believe it" means "I hold it to be true," then these are beliefs that you must have in order to be an atheist.