Eden said - Actually, to be all-powerful is, in abstract, an impossibility.
All of God's traits are mutually-exclusive in the abstract. Only anyone who doesn't stop to think about the implications would claim they aren't.
Yeah, the famous "stone" question is a pseudo-intellectual extra-Biblical (philosophical) exercise that is pointless and unnecessary, since the problem with God's claimed trait of omnipotence is that God blows it in the Bible itself, eg
Judges 1:19
"And the LORD was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron."
So God could do anything BUT overcome those new-fangled high-tech iron chariots....
There are many more examples where God may be claimed elsewhere to know everything and be all-powerful, but the actions recorded for God would tend to indicate otherwise.
Adam