"Some things are necessarily true"
In reading God, Freedom and Evil by Alvin Plantinga I came across an explanation that opened my eyes to logic and necessity a little further.
Atheist or Atheologians as Plantinga puts it are essentially saying of God that:
(1) God is omnipotent
(2) God is wholly good
(3) Evil exists
Their claim is of course that this is logically inconsistent with a God existing. But in terms of inconsistencies, where this argument currently stands, there is no inconsistency with this set of propositions.
The atheologian must adopt certain additional premises which John Mackie lays out:
(4) A good thing always eliminates things as far as it can
(5) There are no limits to what an omnipotent being can do
If in fact these premises are true then in it would follow that
(6) Therefore, God does not exist