Jesus in washing the feet of his disciples is an example of unprecedented humility. No human on this earth would have thought of doing such an act of humility and service.
And to the surprise of many, especially of his disciples, Jesus suddenly takes an action before the Passover feast at the last supper that he would have with them physically to wash his disciples' feet in which Peter wanted to oppose but Jesus told him it was necessary that he washed his feet even if he did not understand it at that time.
Jesus was a living example of virtues and facts that cataloged him as the son of God and came to set an example so that others could not say what example of the teacher they did not have because He shared himself as God himself without defects and perfect in everything he did.
Peter knowing the Lord's clothing is strongly opposed to washing his feet a vile sinner but He makes him see that if he does not wash his feet he would have no part in his kingdom question that leads the apostle to obey.
Actually this was a great lesson that Jesus offered to wash his disciples' feet and taught a lesson in humility and selfless service.
John 13: 1-17
13 Before the feast of the passover, knowing Jesus that his time had come to pass from this world to the Father, as he had loved his own who were in the world, he loved them to the end.
2 And when they had dinner, as the devil had already put in the heart of Judas Iscariot, son of Simon, to deliver him,
3 Jesus knowing that the Father had given him all things in his hands, and that he had come out of God, and went to God,
4 He got up from dinner, and took off his mantle, and taking a towel, wrapped it.
5 Then he put water on a little book, and began to wash the disciples' feet, and to wipe them with the towel with which he was girded.
6 Then he came to Simon Peter; And Peter said to him, Lord, do you wash my feet?
7 Jesus answered and said to him: What I do, you do not understand now; But you will understand later.
8 Peter said to him, Never wash my feet. Jesus replied: If I do not wash you, you will have no part with me.
9 Simon Peter said to him, Lord, not only my feet, but also my hands and my head.
10 Jesus said to him: He who is washed needs only to wash his feet, for everything is clean; and you are clean, although not all.
Who would deliver him? That is why he said: You are not all clean.
12 So, after he had washed their feet, he took his mantle, returned to the table, and said to them: Do you know what I have done to you?
13 You call me Teacher, and Lord; and you say well, because I am.
14 For if I, the Lord and the Master, have washed your feet, you also must wash one another's feet.
It is important to note that the disciples had a constant relationship with their lord but although they already enjoyed a special relationship with Him, this act broadened their intimacy and gave them a great lesson so that they too could do it with their siblings and with their neighbor each time. That was necessary.
Maybe Jesus did not want this act to be a particular practice for the church but it was probably an essential act in his disciples so that they could really understand the act of service.
Jesus knew that many people feel humiliated by having to do this act of service and He simply wanted to show him that service is a fruit of the spirit and that no one should feel humiliated by an act of humility that more than service should be a disposition of the heart .