Visiting the synagogue in Antioch in Pisidia, Paul is asked to speak to the gathering there. Paul points out that though David was the recipient of the promises, it was Jesus who was the promised and long-awaited Messiah, who brought the forgiveness of sins. Paul's speech here is a proclamation of the age of salvation, of the fulfilment of the promises to David and to God's people.
In the Gospel of John, Jesus explains the role of humility in salvation life, after washing the feet of His disciples. He relates Himself to the disciples as a slave to a master, and His action (of washing the feet) and His words here point to a laying down of life for others, as a slave. He mentions the betrayal by Judas at this point precisely because the foot-washing is a sign of His coming death, of the way in which He gives His life for others. He indicates awareness of the coming betrayal to show that Satan can only do what God allows him (cf. Job) and that it is Jesus Himself who willingly goes to His death, to make His life available for others. His death brings about His exaltation and gives glory to God.
Thus it is that Jesus reminds the disciples to "behave accordingly" (John 13:17), i.e. not to be upset by the approaching events but to follow His example and to believe in the thread of love running from the Father to the Son and to all who welcome and believe in Him. Happiness will be theirs.
Lord, help us to welcome all who come to us, and to be humble and self-denying in our reception of God in others. Amen.