Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit. John 13:10.
"Then cometh he to Simon Peter: and Peter saith unto him, Lord, dost thou wash my feet? Jesus answered and said unto him, What I do thou knowest not now; but thou shalt know hereafter. Peter saith unto him, Thou shalt never wash my feet. Jesus answered him, If I wash thee not, thou hast no part with me" (John 13:6-8). Peter found it hard to get his feet washed. Why? Who do you suppose Peter found it hard? Did he think that Jesus, as the Son of God, was above this menial sort of task? Was he feeling guilty already for not having volunteered himself? It was the custom that a servant would wash the feet--and if a servant was not available, them someone would volunteer to do the job. But you don't expect volunteers for this from a group of disciples who have been bickering and arguing about who is going to be the greatest.
Then Jesus said, "If I wash thee not, thou hast no part with me. Simon Peter saith unto him, Lord, not my feet only, but also my hands and my head. Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit" (verses 8-10). Peter had already been washed by Jesus' cleansing power. Baptism, where the head and hands, as well as the feet, are washed, is a symbol of the cleansing of the whole person. The Communion is a symbol of the cleansing needed because of our falling and failing as we grow. When we accept Jesus as our personal Saviour, because of His righteousness, we stand before God as though we had never sinned. And His justifying grace is available to us day by day according to our need.
Because of the example Jesus set in this service, we know that if we are to have a part with Him we will be involved in the communion service in all its aspects. If He does not wash us, we have no part with Him.
Those in the early church followed this practice for a time, but then many found it to be inconvenient, and the practice was largely abandoned. However, the symbol is incomplete without the foot-washing service being included. It is only as we are washed by His blood, cleansed anew, that we are fitted to partake of the bread and the wine that are the symbols of communion with Him.