"'No,' said Peter, 'you shall never wash my feet.'
Jesus answered, 'Unless I wash you, you have no part with me.'
'Then, Lord,' Simon Peter replied, 'not just my feet but my hands and my head as well!'" (John 13:8-9)
"No" and "never" are such strong words, especially when spoken to the Lord of lords, King of kings. Peter was rash, audacious, and outspoken (often unfiltered). Peter meant well because he didn't want his Master to stoop down to wash his feet (a servant/slave's job). He didn't realize Christ's mission theme: "For even the Son of Man did not come to be served, but to serve, and to give his life as a ransom for many." (Mark 10:45)
We are not unlike Peter. How many times have we insisted in our own ways and resisted what God wants us to do? How many times have we thought we know what's best so we dictate what God should do (in our prayers)? We ought to humbly receive God's gifts of grace, surrender to God's will, and trust His doing even when we don't understand. Obedience matters!
Jesus replied to Peter with a lesson on spiritual washing/soul cleansing. Only those who are spiritually washed by Christ's blood and His Spirit have a part in Him, enjoy His fellowship, and share in His kingdom. He saves, justifies, and sanctifies us. By the act of washing the disciples' feet, Jesus also exemplified selfless, sacrificial love and servanthood that we are to imitate. Then Peter wanted Jesus to wash not just his feet but also his hands and head. He wanted to cover all the bases. Don't you just love Peter's personality :)? He certainly had weaknesses. We all do. It's wonderful to know that God does use all sorts of people with various personalities to do His kingdom work.