Quote from Free Thinker:
THE PARADOX OF OMNIPOTENCE:
1. Either god can create a stone that he cannot lift, or he cannot create a stone that he cannot lift.
2. If god can create a stone that he cannot lift, then he is not omnipotent.
3. If god cannot create a stone that he cannot lift, then he is not omnipotent
4. Therefore by definition, god is not omnipotent.
THE PARADOX OF OMNISCIENCE
1 If God does not know all events past and future then he is not omniscient.
2 If God does know all events both past and future (especially future) then he cannot make any decision or choose a course of action, because he already knows his future actions for all eternity. He is paralysed by his own omniscience.
3 If God can make a decision or choose a course of action that he did not know in advance, then he is not omniscient.