Seemed a little weird to me too, back in college. Of course, the easy Occam's Razor answer* is that leaders and philosophers made Him up to serve their own purposes, and purposes change. The less likely and much more interesting answer is that gods can learn, a remarkable concept if combined with the advertised trait of omniscience.

It's worth pointing out that the idea of omniscience is, itself, a logically null concept. How the hell do you KNOW you know everything? How do you prove it? If you didn't know it, you might not know that you didn't know it.

*Occam's Razor answer--not necessarily the correct one--to the deep problems of the historical church with injustice, pain, and suffering in the world:

"God doesn't exist, and shit happens."