This argument is one I have heard at least once or twice, although it appears to be less common than the popular "design argument," "argument from ignorance," and "argument from personal experience." However, it is no less filled with enormous logical fallacies than these more common arguments.
Unfortunately for theists, the "argument from evil" (which is what they are attemptiong to use) doesn't work for them. In fact, it works against their argument against atheists! Why?
Human beings are fallible and definitely not all good! This fact is recognized by theists and atheists alike. I have often met theists who deny that people of their faith who commit atrocities are "not real Christians/ Muslims/ Jews/ Hindus/ etc." However, I have yet to meet an atheist that denies that atheists who committed atrocities, ex. Moe Zedong and Stalin, were "not really atheists."
YES!! ABSOLUTELY THEY WERE ATHEISTS!!
BUT! This is IRRELEVANT to the legitimacy of atheism!
So why does this argument from evil not work against atheists? We don't doubt the existence of evil, and the majority of us don't believe in an entity [natural or otherwise] that is "omni-benevolent" [i.e. All-good]. Nor do we deny that there are evil and/ or illogical atheists among us that occasionally stain our midst, there are.
Yet, the presence of evil among atheists does not destroy the legitimacy of atheism! REMEMBER! Atheism is simply a lack of belief in God/ Gods. Nothing else is universal among us. So, the argument that there are evil atheists is as harmless to the idea of atheism as being hit by a water balloon.
*Also, a little side note: Although Stalin and Mao were definitely atheists, the idea that Hitler was one is up for debate.
It is confirmed that Hitler was raised in the Austro-Hungarian Empire as a young boy and that his mother was a highly religious Christian. I believe I heard that Hitler was raised as a Catholic, but whatever type of Christian he was, he was not an atheist. To my knowledge there is no documentation of Hitler renouncing his faith. [However, some have suggested that he had an interest in the occult - whih still doesn't prove that he wasn't a Christian, btw.]
Back to the argument from evil, we have covered the ground of the harmlessness of using the argument against evil against atheists, but why is that argument beneficial to atheists and detrimental to theists who believe in the Abrahamic God?
There is a simple answer to this:
The traditional and most commonly accepted idea of God is that he/ she is "all-powerful," "all-good," and "all-knowing." [At the same time] The essence of the argument from evil is that there is a TITANIC problem with this notion from the start!
I'll spell it out simply for you:
The three combating notions of the Judao-Christian-Islamic God with regards to evil:
1. God is all powerful
This means that he can do anything, including stop evil and create it.
2. God is All-Good
This means that God would never commit evil.
3. God is Omnicient
This means that God knows everything.
Are we on the same page here? I'm sure many of you Christians and Muslims, etc. would agree with these ideas.
ANY TWO OF THESE NOTIONS CAN WORK TOGETHER IF THEY DISCOUNT THE THIRD! HOWEVER IF ALL THREE ARE ACCEPTED AT ONCE, THEY CONTRADICT EACHOTHER!!
To illustrate my point I will combine 2 at a time and show how the third cannot work with the existence of evil:
1. God is all powerful and God is all good:
Okay, no contradiction here, maybe this God DOESN'T KNOW that evil exists? Sure, that works.
2. God is all good and God knows everything:
Okay, this works too, assuming God can't do anything about the evil that exists.
3. God knows everything and God is all-powerful:
Sure! This works as well, maybe God desn't care about evil? Or maybe God IS evil himself? Evil Gods and Goddesses DID exist in past religions [esp. Polytheistic ones].
But! God is all Good + All Powerful + All Knowing?
THAT DOESN'T WORK!!
Why would evil exist with a god like that?! No matter which way you turn you have to take away one of these qualities to make your god fit.
You don't think so?
Okay! I challenge you, theists, to present me with evidence for why a god with all three qualities could exist with evil! BUT! Be prepared for me to critique your argument and call you out if you omit one of the three qualities!