It’s much more than an assumption that Satan knows who Almighty God IS and Satan knows that Jesus has already defeated him. He knows that because of his defeat it is too late for him, he knows that someday soon he will be cast into a lake of fire where he will spend eternity with all of those he managed to deceive here on Planet Earth.
The question is why would Satan behave this way having already been defeated? I’ve thought about this a great deal and my only conclusion is that he is in his final death-throes. Since his defeat the Devil understands that he is doomed and his future is grim. Hate, deception and fear are among the few tools that remain available to him, (and powerful tools they are). Therefore, the only way the devil can achieve any self-satisfaction is to harm the Church and deceive as many people as he can into believing his lies. He believes (his belief may be true, I don’t know) that the more people that he can keep away from believing and trusting in God, the more pain and distress he can cause Jesus and The Father.
“Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour.”
~The Apostle Peter (1 Peter 5:8)
If there is any advise that could possible pass along to the millions of people in the world who are in bondage to the lies of Satan it is this: Search for the truth and don’t quit searching until you find it. When you find it, accept it and the truth will set you free like you have never been free before!
“I am the way, and the truth, and the life. No one comes to the Father except through me.” ~Jesus the Christ (John 14:6)