A Question Of How We View God.

I've been thinking about how we sometimes criticize God. I've heard people try to use the Old Testament as evidence against His goodness or justice. If He says "don't murder" why did He command His people to go to war? If one of His attributes is Omniscience, then how is it possible Abraham and Moses seem to change His mind with their prayers?

And then there's the classic, "Why does God let bad things happen to good people?" I could get into the fact that people aren't good in the first place, but something else has occurred to me.  When we criticize Him, aren't we appealing to a sense of "good" over God? But if God is sovereign, then doesn't He set the standard of what is good?

I have a feeling our sense of justice is fueled more by our emotions than our understanding. Who has a better understanding of the law? The person who wrote it, or the people who interpret it?