What does John 13:11 mean?

Jesus has just made a statement explaining the nature of the spiritual "cleansing" He offers. Those who are "bathed," meaning saved, do not need to be re-saved over and over. Rather, they need only to have their feet "washed." They need to confess and repent of daily sins in order to be in good fellowship with Christ, but they're already "clean" by virtue of their salvation (John 13:7–10).

At the same time, Jesus explains that not all of those present are "clean," in that spiritual sense. At this moment, only Jesus and Judas are aware that Judas has betrayal on his mind. The other disciples are sincere believers in Christ—they are truly committed to Him. Even if they lack understanding, or, like Peter, self-control (John 13:8–9), they are clean by virtue of that faith. Judas is neither sincere nor submissive. He's played along for his own reasons and will soon sell Jesus to His enemies (John 13:21–26).

The presence of Judas here raises two ideas often lost when discussing this passage. First, Judas is among those whom Jesus serves by washing their feet. Despite Judas being lost, treacherous, and plotting murder, Jesus extends humility and kindness to him. That will continue as they share a meal together: one last gesture of Christ's loving kindness to His own enemies.

Second, this emphasizes that spiritual "cleansing" is not accomplished by rituals like confession. Judas participates in the foot-washing just as the others. But they are already "clean"; he is not. Surface-level religion, without real faith, will not save.