IF God has an Ineffable Plan,
IF everything which has happened, is happening, and will happen is destined to happen,
IF there is no other possible outcome of anyone’s actions (including Judas’s),
THEN Judas did exactly what he was supposed to do.
Without Lucifer falling from Heaven and becoming Satan (God’s Adversary), then there’s no temptation. Without the temptation, humankind is not thrown out of Eden. Without the loss of Paradise, there’s no Chosen People who will one day return to Paradise. Without a Chosen People, there’s no need to send Jesus to Earth to save God’s Chosen People. If Jesus is not sent to Earth, there is no reason for Jesus to sacrifice Himself. Without the need for Jesus’s self-sacrifice, there is no need for Judas’s betrayal of Jesus and no need for Jesus to die. And without all of those things, there’s no Christian Church.
Everything in the universe of this play is causal.