Your task is very simple. Find the flaw in the following argument.
Hypothesis: God does not exist.
Proof:
1. God is, by definition, omnipotent.
2. If he is omnipotent, then he may create an object such that he cannot lift it.
3. If he cannot lift it, then he is not omnipotent.
4. We have a contradiction: he is omnipotent, and is not omnipotent.
5. Q.E.D. God cannot exist.