3:9 And the LORD God called unto Adam, and said unto him, Where art thou?
God doesn't know where they are?
3:11 And he said, Who told thee that thou wast naked? Hast thou eaten of the tree, whereof I commanded thee that thou shouldest not eat?
Again, God doesn't know what happened.
4:6 And the LORD said unto Cain, Why art thou wroth? and why is thy countenance fallen?
Well, Cain was upset because God had dissed him because of his offering of fruits and vegetables.
And God has to ask?
4:9 And the LORD said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?
4:10 And he said, What hast thou done? the voice of thy brother's blood crieth unto me from the ground.
Apparently god is not omnipotent - he has to ask mere mortal men to reveal themselves, why they're unhappy, etc.