God is omnipotent. He can lift every stone and can create a stone he can’t lift. If he created a stone he couldn’t lift, he wouldn’t be omnipotent any more, but right now he is.
But… God is unchanging.
God can make contradictions true. Thus, (3) is false as God can create a stone he can’t lift—and lift it.
But… Does this make sense? And doesn’t it solve too many problems?
Premise (5) is false as omnipotence does not need to extend to impossible tasks. Or if “task” only includes logically possible tasks, then (3) is false, as “creating a stone God cannot lift” is not a task.
Mavrodes: Either God is or is not omnipotent. If he’s not omnipotent, no problem. Suppose God is omnipotent. The “a stone God can’t lift” either is or is not contradictory. If it is contradictory, there is no need for God to be able to do it. If it is not contradictory, then there is no problem for omnipotence: God can create a stone God can’t lift.