Satan was cast out because he was trying to actually BE God and overthrow Him.
God Himself doesn't "need" to be obeyed but we should do it to honor who He is. He doesn't "need" to be worshipped but we should do it because we love Him and are thankful for what He has done.
A personal relationship with God/Jesus and knowing who He is on a personal level is what God really wants from us. Scripture was not meant to replace that. It's like if I wanted to get to know you and you gave me a book someone wrote about you to read...that's a good start but to really know you and separate truth from fiction, I would seek a real relationship with you. A personal relationship with you. And that is what God really wants from us. Relationship. Not religion...relationship.
However, once you get to know Him for yourself and realize how big of a deal Jesus' sacrifice was along with eternal pain-free life that He is offering to us, you WANT to praise God all the time. Once you realize someone loved you enough to die for you and never leave you alone, you WANT to be thankful to God. God extends extraordinary love to all. He is extremely merciful on top of that. In fact two of the men closest to Him in the Bible - David and Moses - were murderers. Jesus' own great great great grandmother Rahab was a prostitute. And yet God forgave them and extended love and favor to them. He does the same for each one of us as well. All He really wants is for you to have a relationship with Him. Try Him...what's the worst that could happen if you believe in Him?
No christian has ever answered this question for me so maybe you can.
If God is all knowing, he knew satan would betray him. So why willingly create your eternal nemesis?