Since abrahamic god is eternal, what was he doing before he created the universe, including heaven and hell?
I don't know, but.......
Eternal may not mean what we think it means. If something cannot come from nothing, then something has "always" existed. However, that something has not always necessarily existed in the same state or configuration. It is assumed by some that God has always existed in a complex configuration -but it is not actually stated in scripture. God may have always been God -always existing and never changing in some respects, but if God creates, then he -essentially being all that can act and be acted upon -makes himself of a different configuration and makes more to be known even if no new "material" has come into existence. I AM may have always been a true statement, but the definition changes with each change. If no new material can come from nothing, then eternity may be a matter of infinite subdivision. We, ourselves, are a part of the whole -made separate persons by arrangement. In creating us, God essentially separated a part of himself which could then be independent of him by decision -and even create things which are new to him.
Joh 14:20 At that day ye shall know that I am in my Father, and ye in me, and I in you.
That is actually true if "evolving" is not limited to element-based life and its broadest definition is considered.
It is not actually against scripture for "God" to have once been the most simple state possible -and to have self-developed.
Not considering "God" for a moment...... If earthly life represents the first self-aware intelligent beings, it could still at least be said that eventual self-awareness and intelligence is inherent in that which exists. In our cases, we represent a portion of all which exists -and are aware of only a portion of all which exists. It is also true that even though our environment is already in motion and interacting according to logic, there are some things which cannot happen without intelligence and self-awareness.
We may find that this is true of everything -that "God" -everything and the mind thereof -must have possessed or developed self-awareness and intelligence for things to become as they are.
Is it more logical that complex configurations and order such as the universe and periodic table develop in tandem with an overall intelligence and self-awareness -or for extremely complex configurations and order to develop first and alone -eventually resulting in mass-produced self-awarenesses and intelligences?