Now before the feast of the passover, when Jesus knew that his hour was come that he should depart out of this world unto the Father, having loved his own which were in the world, he loved them unto the end. John 13:1 (KJV)
This supper was intended to set in their hearts a memory of his love for them. The foot washing and the communion are both acts of cleansing and surrender. For us who read about it 2000 years later the story still carries multiple messages.
Three of the gospels tell the story that includes the communion and its elements of bread and wine. Only John tells of the foot washing and the extended teaching on that evening. But the whole story of that final night is full of his knowledge that he was leaving them to return to his Father. He had this last chance to repeat things, to impress on them his love for them, and to establish them as leaders and disciples.
In the teaching there are times of testing. After he finished washing their feet he put on his robe and returned to sit with them. Then he asked them if they knew what he had done. He wanted to be an example that they should repeat to each other and to those who would come later.
In the years since he gave us this lesson we seem to have sometimes lost the message of love and service. Leaders of the church are called to be servants of humble attitudes, rather than dictators of fashion or masters of repartee. We live in the world and these worldly accomplishments are the product of worldly attitudes. Jesus calls us to set our minds and hearts on higher goals. Love and service do not sound grand in the world's scheme, but from Heaven's perspective they are. This is what Jesus calls us to do.