If god is possible, then god necessary exists.

Well i wish i could really make sense of these statements.
If his possible then he exists,unicorns are possible.I believe in fairies at the bottom of my garden ,they leave so many clues i have to believe in them.

Similarly to xris, I feel that if an ontological argument is a good argument for a supernatural being, then it's a good argument for any supernatural being.

1. We can say that "God might not exist." That would by the criterion make God a contingent being as much as John in the example.
2. The second part of the argument, if I read it correctly, seems to be that if we understand what it means for something to have contingent being, then we understand what a non-contingent being must be like.
2.a The argument from opposites is about the meaning of them, not their actual existence. We can know what "no" means without any knowledge of "yes" as any parent knows.
2.b To say that we can say X may or may not actually exist doesn't imply or prove that there is a X that cannot help but exist.

3. To the second example and argument, the same retort could be made. John may or may not speak fly, and able-to-fly is a property that is contingent upon John actually being able or not. But does this mean that there must be a person who by necessity is able-to-fly? No. All it means is that we are able to know what flying is (we see birds flying, airplanes, etc.).

4. The argument that if there is a God, then it must necessarily exist because that is what Gods do, is dependent on God existing, a premise that can be denied.
5. If God is good, then God is good. There is no reason to suppose that God is good by necessity unless you define It as good. One can imagine a God that is evil, or only partly good (Zeus, for example).

I hope I am understanding the original argument properly; if so it doesn't seem to prove the conclusions wanted.
Regards,
John