That's right he can, but the point is he has an actual form that is the cause of any other form he may take
(did you know the english language originally developed as a trade language between nations as opposed to a language for philosophical dilineation???)
eternal means always existing - this is why I gave the example earlier of the sun and the sunshine - they both exist at the same time because you cannot seperate them - but it is recognised that the sun globe has a quality distinct from the sunshine - namely that the sunglobe is the cause of the sunshine. Actually god is not the only thing that is eternal, so is the consciousness of the living entity, the raw elements of material creation, and time itself. The difference between these eternal things and god (who is also eternal) is that god is the cause of these other things - in otherwords just as the sunglobe never appears without sunshine, god never appears alone.
The origin of all (or adi in sanskrit - the first) indicates that there is nothing else that is on the same "level" as him (just in case you have ideas of god's position being usurped or tha someone else can manifest a universe) and the cause of all causes indicates that his will is omnipotent (whatever we perceive in terms of effect ultimately owes its cause to god - in otherwords he has the final say). True all the terms are quite similar but they illustrate different aspects of the absolute - when people say "God is great" they really don't know what "great" really means
Anyway I am sure that someone possessed of your incredible skepticism will have a few things to say about this, but to continue ....
No .... I just said that he created the living entity, the material cosmos and the time factor which are all possessed of the same eternal potency just as the sunshine is eternally the companion of the sun - there is no possibility of seperating the effect(sunshine) from the cause (sun)
He doesn't have to create it, just like the sun doesn't have to create sunshine - its a natural consequence between the energetic and the energy.
Its not like you have to manufacture wetness out of water
Its not like you have to create heat from fire
Its not like you have to create voltage from electricity
Something that is energetic (or something that is the source of energy) automatically manifests the qualities of energy - that's why you can test the nature of fire with a thermometer or the energy of a powerhouse with a voltage reader.
Saying that god cannot cannot be god without eternity is like saying fire cannot be hot without flames -
- It is assumed that when you are talking about a fire that you are talking about a fire with flames since a fire without flames is an absurd imagination. Talking about how god is going to develop the quality of eternity is like talking about how water is going to develop the quality of wetness - It already has the quality, and it is by perceiving the quality that you come to understand the object in the first place!!