What is wrong with this premise?

[Darkstar]

The notion of God existing outside of reality is nonsensical. I never made that claim.....I never would make that claim.

Perhaps I misunderstood you. Earlier you said:

I often hear atheist ask that if it is possible that God has always existed why can't it be possible that the universe has always existed? Which is a good question(although I would use "reality" instead of universe).

Since the premise can be used to exclude reality from the cause and effect cycle it is not specific to God.

I had assumed that you meant god existed outside of reality, rather than outside of the universe (e.g. in a multiverse, perhaps).

Now then:

Mathmatics is something and as far as I am concerned its existence is eternal. Nothing has ever caused 2+2 to equal 4. It just always been that. It requires no cause.

This is actually false. It could have been apple pie + magic fairies = elbow if the terms had been defined differently. Numbers are abstract concepts invented by humans to model reality; they are not absolutes in and of themselves. That is, they are axioms rather than universal truths.

I found this interesting video on the subject that explains this better than I can: