Hygiene and comfort go together, so do holiness and spiritual cleansing (taking away sin).  In a hot dusty land, without hot and cold running water, visitors to a large house would be greeted by a servant who would remove the guest’s sandals and then wash their feet with fresh water and carefully dry them with a towel.  It was a mark of hospitality, a very personal way to honour the guests.  However, at the Last Supper, there was no servant in the borrowed home (Matthew 26:18-19).
 
Of course, in a house with no servants, people would wash their own feet.  But on this occasion, Jesus took the servant’s role.  Dressing like a servant, with a towel around His waist, He started to wash their feet.  It was intensely personal, very humble and not the sort of thing He should be doing, according to Peter.  He felt that it would be an insult to the Lord to allow Him to wash his feet.  

It was a parable acted out in front of the disciples.  In addition to sacrificially meeting the basic needs of His team, thereby teaching the nature of practical love, Jesus was also insisting that unless He washed people clean spiritually, they could not belong to Him.  Realising his inner guiltiness, Peter then overreacted forgetting the purifying effect of believing the truth Jesus had spoken throughout His ministry (John 15:3).  Jesus did not consider Him an outsider but wanted to wash away the dirt of that day.  It was a picture of how His blood would clean every guilty conscience (Hebrews 9:14).
 
Many believers realise their failure to keep clean.  Some even doubt that they are saved.  But those who have trusted in Jesus, as their Saviour should be reassured that: “… if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin." (1 John 1:7).  However, fellowship with God needs continual refreshment, like dry and dusty feet.  When we let the dirt of the day cling to us, we need to be washed clean again by Jesus.  We fail when we think that we can make ourselves clean by our religious observance or our attempts to mend our broken ways.  Jesus knows that we cannot regain sweetness of fellowship with Him unless He washes us.  So, humble yourself and admit your need to be clean – confess your sin and let Him take it away.