What to say when somebody asks about the big bang

[Aegon]

Are you perhaps defining "God" as that which has always been there?  Even if you refrain from importing other baggage into the term, it is questionable whether anything enduring has always been there.

If matter/energy cannot be created nor destroyed but only transformed, then somethingness has always been here changing forms.

Could it be that all the energy of our universe was contained within the "God", and the "God" transformed itself into the universe? Is this already a belief? Or does it not make sense?

EDIT: Looks like I'm describing Pandeism.