Do you know what I have done to you? You call me Teacher and Lord—and you are right, for that is what I am. So if I, your Lord and Teacher, have washed your feet, you also ought to wash one another’s feet. For I have set you an example, that you also should do as I have done to you. Very truly, I tell you, servants are not greater than their master, nor are messengers greater than the one who sent them. If you know these things, you are blessed if you do them. (“Ei tauta oidate, makarioi este, ean poiēte auta.”)
[…]
Whenever I hear this reading proclaimed on Holy Thursday, I never fail to think how different Christian churches would be if, in addition to our weekly celebrations of the Eucharist we celebrated the Footwashing. It may sound crazy, and it would be terribly complicated to arrange every Sunday—all those basins of waters and towels and shoes and socks!
But imagine the symbolism if every week the presider laid aside his vestments and got down on his hands and knees to scrub the feet of his parishioners. What a reminder it would be to all of us—priests included—that this is what Christ asked us to do in addition to the celebration of the Eucharist. After all, what he says about the Eucharist, “Do this in memory of me” at the Last Supper in the Synoptics, he also says about the footwashing in John: “If you know these things, are you blessed if you do them.”
Seen every Sunday, over and over, the washing of the feet might help us see how power is more intimately linked to service. (Fr. James Martin, SJ, Jesus: A Pilgrimage
Mysteries and Manners 