Here is the logic:
The universe had a beginning, as evidenced by the detection of the Big Bang.
Anything that begins to exist must have a cause.
Therefore, something caused the Big Bang. (and thus the universe)
Abstract things like numbers may be unchangeable and eternally the same, but they can't create anything. Only a personality can
If God is uncaused, (exists by nature), and is a personality
then God is eternal, timeless. and the creator.
You can read more about the logical steps here in William Lane Craig's book, On Guard.
Here is the logic: The universe had a beginning, as evidenced by the detection of the Big Bang. Anything that begins to exist must have a cause. Therefore, something caused the Big Bang. (and thus the universe) Abstract things like numbers may be unchangeable and eternally the same, but they can't create anything. Only a personality can If God is uncaused, (exists by nature), and is a personality then God is eternal, timeless. and the creator.
You can read more about the logical steps here in William Lane Craig's book, On Guard.