Exactly. "God" is simply the archetype of that which is perfect and whole (thus: "holy"). God is also the archetype of that which is the origin of things. If you want to look at it scientifically, God is whatever caused the Big Bang, and created the Universe as we know it.

People personalize it because it's their nature to personalize things. After all, they often personalize their cars, don't they? I've heard people yelling at their cars and pleading with them... ;-)