What does John 13:31 mean?

The gospel of John has made several references to Jesus working according to a divine schedule (John 2:4; 7:30; 8:20; 12:23). Here, again, Christ refers to something happening according to a set timetable (John 12:23). The ultimate purpose for which Jesus was born as a man is at hand: His sacrificial death (Matthew 16:21). This comment seems deliberately withheld until after Judas is dismissed (John 13:26–30).

Jesus will refer to the concept of glory several times in the next few verses. The death and resurrection of Jesus are pivotal moments in mankind's relationship with their Creator. The idea that God would come in human form, die an unjust death, and use that sacrifice to pay the penalty of human sin is incomprehensible. This act of outrageous mercy glorifies God, proving His love and mercy. In a sense, this verse is a glimpse into the mind of God. What our instincts tell us is shameful and barbaric is going to be used for the greatest possible good.

This verse again uses the term "Son of Man," which relates to a prophecy in the book of Daniel (Daniel 7:13). This is a title applied to the Messiah, one Jesus uses often for Himself.