Somebody in my house meeting meant that he thinks when Satan gained the authority over the world and over mankind God asked Satan what he wanted to give it back and Satan said something which he thought God could never fulfill: A perfect sacrifice. I do not believe this at all. God did not try to pay a price to Satan. It was all about God's righteousness and not about Satan. I think the thought that God had to pay a price to Satan is ridiculous. Anyway, I don't understand this verse here. If Satan had really known that Jesus would defeat him on the cross he would never have killed him, but then why does Peter try to keep Jesus from completing his mission and Jesus even rebukes him calling him Satan? This sounds as if Satan knew that Jesus had to die. Did Satan not have demons all around which heard what Jesus said that he has to die? Why did Satan not get it? Why didn't he understand that this would be his defeat? Or did he know it? But if he knew it he would not have killed him. Mat 16:22 Then Peter took him, and began to rebuke him, saying, Be it far from thee, Lord: this shall not be unto thee. Mat 16:23 But he turned, and said unto Peter, Get thee behind me, Satan: thou art an offence unto me: for thou savourest not the things that be of God, but those that be of men.