Atheism is unreasonable

[Jenny A]

OP,

Let me summarize what you've said and you can tell me where I got it wrong:

Life began either naturally, or supernaturally. There is no middle possibility (Actually there is. A number of theists believe god created life using natural means, but I'm willing to ignore that for the moment). Because no one has created life in a lab or recorded it forming from inanimate matter, therefore life was created supernaturally.

The formula would be

If A than not B and if B than not A.

But, you have taken a gigantic leap and posited:

If there is no proof of A than B. That is illogical since there is no proof of B either and one could just as well say if no proof of B than A.

Let's apply your formula to something that really has no middle ground. I toss a coin here at my desk. It will land either heads up or tails up. But you can't see it. So if you can't prove it's heads, does that mean it's tails?

Or take a real world situation. For centuries humans applied your formula to lightning, i.e. we can't prove how it occurs naturally, therefore god did it. Now we can show how it is caused naturally. Surely you don't believe god did it until we discovered how nature does it.