Dear Matthew:

Satan can only know what God tells him, or what he is able to  pick up by observation and intellectual discernment and deduction. Since the intellectual prowess of angelic beings is considerable, they would be able to figure out many things from the available evidence.

As to what Satan knew at the beginning we cannot know. Some suggest that Lucifer had some understanding of God's plans for human beings and that contributed to his rebellion.

Certainly the devil knows God's salvation plan now as he can read it for himself in the Bible and from the Prophets and from the Church.

It appears that Satan did have some understanding of Jesus' mission since he tried to tempt Jesus and used St. Peter to try to dissuade Jesus from his mission. Yet the devil can't seem to help himself -- he still facilitated the arrest, torture, and death of Jesus, only to have Jesus rise from the dead and defeat the devil once-and-for-all. It seems to be in the nature of the devil to be an idiot in this regard -- to be his own worse enemy.

Despite his knowledge of these things he may be either delusional about his winning the battle against God or is just trying to do as much damage as he can before he is thrown into the bottomless pit forever.

It reminds me of the story of the frog and the scorpion. The frog and the scorpion were stranded on a little island during a flood. The waters were rising to eventually overrun the island. They needed to get to shore to survive. For the frog this was no problem since he could swim, but the scorpion could not swim to shore.

So, the scorpion asked the frog if he could ride on the frogs back. This way they could both get to shore. The frog refused saying, "No, I will not allow that because you will sting me and I will die."

The scorpion said, "Why would I do that? If I stung you we would both die in the river."

So the frog allowed the scorpion to ride on his back while he swam the river to shore. In the middle of the river, sure enough, the scorpion stung the frog. The frog cried out before he died, "Why did you do that? Now we both will die."

The scorpion said, "You should have known better. It was in my nature to sting you."

Interestingly enough in the Bible one of the words used to describe a demon is "scorpion."

God Bless,
Bro. Ignatius Mary