It is important to note that John connects the footwashing by Jesus with his knowledge of his status and functions. His status was his pre-existence in heaven and his future glory in heaven; his function was that he was in control of all things, that he had been assigned this role by the heavenly Father. It is against the background of these high privileges that we are to see his humility.
This action of Jesus was not merely the action of a servant; rather, it was the duty of the lowest servant. None of the disciples seemed concerned about washing the feet of Jesus; after all they were the government in waiting. But the true king was delighted to wash their feet. Sometimes actions speak louder than words.
There is an important lesson from this incident for our Christian service. These men in the Upper Room were being trained for serving God. They needed an encounter with the humble Christ before they could understand how to serve God. And they needed to learn that the bigger the task (Calvary), the greater the humility. In all likelihood, Jesus was performing an acted parable for the benefit of his disciples. Jesus shows that pride has no place in the service of God. Before we can serve Jesus, we need to imitate the humble Jesus.