Brother, your post makes me think about this: How could Satan not know the purpose of God with His son Jesus? He knew the purpose of Jesus in this world and that´s why he even tried to tempt Him. Or are you saying God used Satan in order to make Judas fulfill the plan?
Joh 8:43 Why do ye not understand my speech? even because ye cannot hear my word.
Joh 8:44 Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
Joh 8:45 And because I tell you the truth, ye believe me not.
Joh 8:46 Which of you convinceth me of sin? And if I say the truth, why do ye not believe me?
Joh 8:47 He that is of God heareth God's words: ye therefore hear them not, because ye are not of God.