Ar, hold on, hold on. This is how I used to think, but you are imagining god in space and time. There cannot be a 'point' of motivation when there is no time. There is a point in our universe where it was created from our perspective, but outside of this universe that point must appear to be everywhere to an omnipotent being.
So while billions of years passed between the creation of the first angel and the creation of the first man [biblically speaking, and I'm not trying to hold you to the bible here], no time passed for God because he is outside of time. That's the idea?
Yeah, I'm gonna need a beer, too. I see where you're heading on it, but I can't get there from here. Not yet.
In God's Debris, there is an interesting thought on this. What motivates an all-powerful, all-knowing being? The answer proposed by the character in the book is an interesting one that I won't reveal since it's sort of a surprise. But you can download and read it here: http://www.andrewsmcmeel.com/godsdebris/