The Highest Position of All - Joyce Meyer

He who is greatest among you shall be your servant. Whoever exalts himself [with haughtiness and empty pride] shall be humbled (brought low), and whoever humbles himself [whoever has a modest opinion of himself and behaves accordingly] shall be raised to honor.
—Matthew 23:11-12 AMPC 

Jesus was able to wash His disciples' feet because He was free. Only a person who is truly free, one who is not insecure, can do menial tasks and not feel insignificant as a result. 

So much of our worth and value is connected to what we do that it makes it very difficult for us to enjoy serving. Serving others is not viewed as a high position, and yet Jesus said it is the highest of all. Serving others also sets them free to love. It disarms even the most hateful individual. It is actually fun to watch that person's amazement when he realizes he is being served through love. 

If someone knows full well he has done us wrong, and we return his evil with good, it begins to tear down the walls he has built around himself. Sooner or later he will begin to trust us and start learning from us what real love is. That is the whole purpose behind being a servant, to show others the love of God that He has shown us so that they too can share in it—and then pass it on.