I've always been a bit confused by Satan in his dealings with Christ. We know that Satan is familiar with scripture for the temptations with which he assaulted our Lord in the desert prove that. What I not sure of is if Satan knew of God's plan for man's salvation, specifically, how it was to be accomplished. Did Satan know that if Christ died in our stead that he would defeat death and Satan's hold over man? Was Satan's pride so great that he was at a loss as to see how to defeat Christ's mission in our world? In reading the Gospels it seems apparent that Satan was confused and wasn't sure what to do about Christ. Consider the following points that I present and see what you think.
At the very beginning of Jesus' life Satan tries to have Him killed by Herod in the massacre of the innocents of Bethlehem.
Afterwards instead of trying to have Jesus killed, Satan tries to destroy Jesus' plan of salvation while in the desert by tempting Him. Had he succeeded in tempting Jesus' human nature to sin, then it would have been all over. Satan hoped to use the Lord's weakened state from hunger and thirst from 40 days in the desert against him.
Jesus entered Nazareth and while in the synagogue he read to the people about the messianic prophesy in Isaiah and told them that the prophesy was being fulfilled in Him. That admission riled up the crowd. I believe that Satan at this point put it in their heads to kill him so they brought Him to the edge of a cliff to throw Him off. We are told He walked through their midst and left Nazareth unharmed.
In John 8:31 we read that Jesus debated with Jews who had believed in Him and Jesus finally says to them “Truly, truly, I say to you, before Abraham
was, I am.” This was blasphemy and both the unbelieving Jews and those that did believe in Him picked up stones to kill Him. Again, He escaped.
In John 10:22-23 He tells the Jews that "I and the Father are one." thus making Him equal to God which again is blasphemy. The Jews pick up stones to kill Him but we are told he escapes again.
When Jesus predicted His death in Jerusalem Peter took our Lord aside and said, "God forbid it, Lord. That shall never happen to you!" Here Jesus tells Peter, "Get behind Me,
Satan! You are a stumbling block to Me; for you are not setting your
mind on God's interests, but man's."
Why would Satan induce Peter to say such a thing? Did Satan finally realize that the death of Jesus is what would save man? Satan seemed to change tactics again. Instead of trying to have Jesus killed Satan seems to have tried to change Jesus' mind and used His friend Peter by appealing to His emotions and keep Him from going to His death thus saving man. Satan seemed very unsure of Himself regarding God's plan at this point. It wasn't until the very end that we see Satan trying his utmost to prevent Jesus' death for by then I believe Satan now understood God's plan of salvation came with the sacrifice of His Son and he tried to prevent it.
The very man that had power of life and death over Jesus was Pilate. I find it very unusual to see that Pilates wife was troubled by dreams of this holy man, Jesus. So much so that I believe Satan induced these dreams as a last ditch effort to keep Jesus from being sacrificed. Pilates wife did everything in her power to persuade her husband not to have anything to do with Jesus. To no avail.
And finally, through all the pain and suffering that Jesus was going through while nailed to the cross, He was continually tempted to "come down from the cross and save yourself!" I cannot imagine the fortitude it took on our Lords part NOT to come down off His cross for he surely could have done it. Yet had he come down from the cross our Lord's mission would have been in vain and Satan knew it then.
So did Satan actually know Christ had to die to save man or did he not know? The best answer I can give is that he didn't know for sure, that is why we see Satan trying to have Jesus killed and at other times trying to keep Jesus from going to His death.