Fun fact, if you arrive at this conclusion as an 8 year old in Sunday school at your ultra fundamentalist Baptist Church and proceed to tell the teacher, you get yelled at and spanked by the teacher and your parents! Ask me how I know.
There are many good arguments against God. This is not one of them.
It’s a slightly more complicated version of whether God can create a rock so big he cannot lift it. Can God create a universe where I simultaneously have freewill and also don’t have the ability to do anything outside his will (evil)? Can 0 equal 1? The answer to that question isn’t yes/no, it’s that the question is invalid. Freewill does not equal non-freewill. It’ll confuse some unprepared Sunday School teacher, but that’s it.
I agree, this is not a good argument against the existence of god, but it seems to be a fine argument against certain models of god. To get out of the paradox, one must be willing to give up certain notions about god. Either:
- God isn’t all knowing, so it’s unaware of all the evil in the universe.
- God doesn’t have infinite power, making god unable to create a universe without evil (perhaps due to limitations of what god can and cannot do.
- God is not entirely good or god’s definition of good does not align with what us humans have been taught. God doesn’t see evil where we see evil so it does not use its infinite power and knowledge to change it.
I think there are a lot of theists who would have trouble accepting one of these notions, which would keep them stuck within this paradox.

