It was an ancient hospitality custom that the lowliest person in the host’s household should wash the feet of guests before they entered a house. We read in John 13:1–5 that at the Last Supper, Jesus washed the feet of the twelve Apostles:
Now before the feast of the passover, when Jesus knew that his hour was come that he should depart out of this world unto the Father, having loved his own which were in the world, he loved them unto the end. And supper being ended, the devil having now put into the heart of Judas Iscariot, Simon’s son, to betray him; Jesus knowing that the Father had given all things into his hands, and that he was come from God, and went to God; He riseth from supper, and laid aside his garments; and took a towel, and girded himself. After that he poureth water into a bason, and began to wash the disciples’ feet, and to wipe them with the towel wherewith he was girded.
By washing the feet of the Apostles, Jesus was demonstrating to the Apostles how important it is to be humble and to serve one another. Furthermore, Jesus bade the Apostles do the same, as we read in John 13:12–14:
So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you? Ye call me Master and Lord: and ye say well; for so I am. If I then, your Lord and Master, have washed your feet; ye also ought to wash one another’s feet. For I have given you an example, that ye should do as I have done to you.
On April 2, 2015, Pope Francis washed and kissed the feet of male inmates from Rebibbia and female inmates from a nearby female prison. The Pope, however, was not following Jesus’ example. Jesus washed the Apostles’ feet and wiped them with a towel. He did not kiss the Apostles’ feet.
While I disagree with this practice of the Pope to wash and kiss the feet of male and female inmates—some believers, some non-believers—there is a chance that his doing so might bring about a change in the hearts of some.