And yet, John 17:12 Jesus says He did lose one—Judas. Jesus is talking about the 12 disciples. After talking about the 12 disciples whom God gave Him, He THEN talks about disciples in general who will be converted by their preaching in verse 29.
Disciple is like unto the meaning of student. Apostle is the equivalent of teacher.
As for Judas,we don't know that Judas was lost.
Judas returned to the temple elders the 30 pieces of silver he was paid so to identify Jesus to the temple guards. Notice? One piece of silver for every year of the age of Jesus before he started his three year ministry.
Judas repented of having betrayed Jesus,though that insured Jesus would fulfill the prophecy of the slaying of the lamb,and then Judas cursed himself by hanging himself from a tree.
"Cursed is he who hangs from a tree."
God has mercy upon whom he decides to show mercy.
Jesus told Judas,who had received the first supper that would become the last supper ritual, to go and do what he
must do.
The Disciples were armed with swords. What chance would Judas have had to leave that upper room? After they learned one among them would betray Jesus if Jesus didn't will it so?
The Son of Perdition,Satan,is not forgiven.
The text doesn't say Judas,whom we are told was possessed by Satan,was not forgiven.
With Satan ,the adversary, within Judas, Judas was not responsible for those actions committed by the enemy. Judas was merely the vehicle through which it occurred.
I think that realization,what Satan had led him to do, when Judas realized Jesus was to be hanged,crucified on a tree, is what led Judas to kill himself ,curse himself,in the same manner. Hanging by rope,not crucifixion.
Guilt.
But if Satan was within, Judas was not the betrayer. Satan was.