how could the very first intelligent, sentient brain (whether Homo Sapiens or alien - for those who blame it all on extra-terrestrials) have even "gone there" without anything pulling it in that direction?
Imagination (I can't believe you left out this BIG factor) and a need to find "explanations" for natural phenomena like rain, lightening, day/night progression, etc.
Something/someone all powerful, they may have thought, was doing these things. Over time stories, legends, led to "beliefs".
BTW if you've ever seen "Through the Wormhole", the show Freeman co-created and hosts, you wouldn't be surprised he thinks we invented gods.
I lean towards that thinking myself.
edit on 6/10/2012 by Chamberf=6 because: (no reason given)