From my recollection of Catholic school, Judas was tempted into being the betrayer, but his legacy as the betrayer is due to his abandoning his faith in Jesus and refusing to confess his sins. Both Judas and Peter are supposed to have betrayed Jesus on Good Friday, but Peter repented while Judas let his guilt drive him to suicide.
The message is supposed to be the devil tempts us all, and failure is inevitable, but God/Jesus forgives all.