I think that the nature of God’s existence is far beyond what we can explain fully. We cannot possibly understand what it means to be outside of time, but perhaps the lack of time for an omnipotent God is not an issue. After all, can the element of time, or the lack thereof, limit an omnipotent being?
And the idea of eternity past is meaningless outside of assuming time. It logically demands a simultaneous being of all reality, even existence and nonexistence would have to true simultaneously.
We cannot resolve these type of issues but then again, that is why we live by faith. What ever the explanation for these questions are, arguing right or wrong is unresolvable and grace is a means of keeping the unity of the Spirit in the bond of peace.
Doug