Regarding my interpretation of Judas's sin and Peter's denial, please realize that not all proponents of openness agree with my particular understanding. Not all Calvinists agree on how to interpret each passage either. In my book, I do say that it is not necessary to agree with Klassen's interpretation, so I go on to give other possible readings compatible with openness. L. D. McCabe, a 19th-century Methodist openness proponent, believes God removed the free will of Judas and Peter in these particular circumstances in order to accomplish his purposes. Thus, they were not morally responsible for their actions. But then you ask, if Peter is not morally responsible, then why does Christ rebuke him for his actions in John 21? McCabe's answer, in my opinion, needs some modification.
If I were to go in this direction, I would highlight Jesus' statement in Luke 22:31 that Satan is after Peter, which is why Jesus tries three times to get the disciples to pray with and for him in Gethsemane. They needed to be spiritually prepared for the events ahead. They let him down and were not properly prepared. Peter was to have a special role in God's forthcoming work, so God works especially with him. At this point, I would modify McCabe and say that Peter was free to acknowledge his relationship with Jesus, but he was spiritually unprepared to do so. Jesus knew this well and made the prediction. All that need be determined by God in this case would be to have someone question Peter three times and a rooster crow.
As for Judas, all three synoptic Gospels say that Judas made his ...1