I think this was one of the main theological discrepancies I had that led to me disbelief. I remember, when I was younger, being taught that god gives us free will and that we are to come to him by our own choosing. When you actually read the bible though, it is god who controls the will of man and only comes to him by his will alone. This is a blatantly untrue theological teaching. If you have free will then god has no domain over your life, and if god has no domain over your life, then god is not all-knowing, present or powerful.
The thing that is confusing about Judas is that the church teaches that he is the ultimate betrayer. So, if he is possessed by the devil, then how could he possibly be doing gods will? The answer is rather easy . . . according to scripture, god willed for judas to betray christ in order to fulfill the prophecy. So, if this is reasonably so, then how could anyone (within the faith) look at judas as someone possessed by something other than god. It is not logical that we should look at him in an "ungodly" fashion. Judas, according to scripture, performed the will of god to put jesus where he needed to be to save mankind. Isn't he then more important than any of the other 12? Is he not holy for having done the will of god so that the prophecy might be fulfilled?
The bible is all over the place when it comes to the argument over free will or predestination, so we have to be smarter than the bible (as is in most cases) to determine reality. Fact of the matter is that, according to the bible, judas was predestined to betray jesus. Therefore, judas (as a character) should hold no fault for the death of christ. The fault should lay with god him(it)self.
There are many other verses and theological disputes within this topic that can be pointed out, but for the sake of the character himself (judas), he is not at fault, within the storyline for the death of christ. Christ's father alone is at fault for the death of his son. He caused a faulty world, of his own creation, that needed to be saved from itself for the short comings of itself. If it were granted that judas had free will, then this would be a different conversation. However, according to the almighty bible, judas was chosen by god to betray his son / himself. In the end, as a believer, if you are to love the trinity, the mother, the wise men, the disciples otherwise . . . . you must also be thankful and grateful for judas. Without him, jesus would've kept on a preachin' til some other predestined bloke came along by way of god.
I haven't even discussed how the other gospels handle this issue.