“I contend that we are both atheists. I just believe in one fewer god than you do. When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.”
When you understand that the theistic definition of God doesn’t allow for the existence of multiple gods, then you will understand why that quote is nonsense.
And I contend that atheists do have at least one god -- and multiples one usually.
Two examples just from the New Testament:
* "For, as I have often told you before and now tell you again even with tears, many live as enemies of the cross of Christ. Their destiny is destruction, their god is their stomach, and their glory is in their shame. Their mind is set on earthly things." (Phillippians 3:18)
A glutton's god can be his/her tummy.
* 5 Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry." (Colossians 3:5)
Greed can also be an atheist's "replacement" God.
It can also be lust. Or just self-worship in general.
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Aside from then this being simply a "mathematical" issue -- as your quote portends -- with Mormonism 'tis also an entirely different GOD altogether.
Your choice...
BTW; that was a quote from WHOM?