This was an interesting verse for me to read. I'll be honest - sometimes I read the Bible and 'nothing'. No insight, no understanding, zippo. Other times, I'll do a little research and things begin to get clearer and I can get a general idea on what God is really saying. This verse - even after all the research I did - came up differently to me than anything else I read. So - I can't say it's dipped in educational background or scholarly rhetoric - it's just from little ol' me. So here goes it.
Why is Satan walking in with the angels? I don't get that. Then it hit me - Satan, the master of disguise. . . maybe the angels don't realize who he is - is that possible? But notice that God doesn't rebuke the angels for hanging out with Satan - He speaks directly to Satan, himself. If this is true - if even the angels can be fooled by Satan, who are we to ever think we can come up against him without Jesus on our side. Who are we to ever think we can make it to get up out of bed without running into something Satan has cooked up for us and never even realize it. Thus the importance of morning quiet time - to get armed with Jesus before Satan ever has a chance to attack.
Satan answers God's question. He's not simply stating where he'd been, he's bragging. He's relishing the fact that he has been all through the earth and has inhabited the people there and had such an effect on them. We know that this is true of America today, but is it true in our own lives? If Satan had come to our door and toured our homes, would he be able to brag to God like he does here in verse 7? Would he be able to come in unknown, unrecognized and welcomed.

Oh God - we need You.