I've been getting this response a lot lately and seen this argument posed by theists on this site as well. I would personally just like to clear things up with anybody using this argument.
Firstly: This argument isn't even valid with most Atheists. It is only valid if you are arguing against a Gnostic Atheist. The Agnostic Atheist, which is by far more common, by definition believes that it CANNOT be proven that a God doesn't exist.
Secondly (if you are arguing against an Agnostic Atheist):
I get the point that you're trying to make-you're saying that an assumption can only be disproved with with contradictory evidence. This is true; however it is not a strong point that you're making, since it is impossible to disprove anything that is unverifiable on a practical level. For example: Can you find contradictory evidence to the assumption that rabbits live in the centre of one of Jupiter's moons?
Even though it technically is impossible to disprove the existence of a God, I still put it in the same category as rabbits living in the centre of one of Jupiter's moons and so does a lot of other atheists on this site.
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