Question of the week: Does God have his own time dimension that eternally exists with him?
My answer: God fills and operates everywhere within all the space and time dimensions and other possible dimensions (not necessarily space or time dimensions) that he has created. The Bible declares that God created the space-time dimensions that govern the universe. The space-time theorems establish that a causal agent beyond space and time created the cosmic space-time dimensions. See The Creator and the Cosmos, 4th edition, for details and documentation.1
The Bible states and the space-time theorems imply that God in no way is limited to or by the space-time dimensions. He is free to operate independent of all the dimensions he has created. For example, he was experiencing what we would interpret as temporal phenomena (love, relationships, planning, beginning his works of redemption) before he created the time dimension that governs the universe. Furthermore, the only dimensions that exist are the ones God has created. To use theological terms, God is simultaneously transcendent (beyond space and time and all other possibly existing dimensions) and immanent (always present and operating within space and time and all other possibly existing dimensions).
Among the books that undergird the world’s religions, this doctrine of God being simultaneously transcendent and immanent is unique to the Bible. For much more on God’s transcendence and immanence and on God’s extra- and trans-dimensionality, see my book, Beyond the Cosmos, 3rd edition.2 Anyone can get a free chapter at reasons.org/ross.