In John 13:1 – 4, knowing that His hour had come and that He had been given all things, was presented as the reason that Jesus got up and washed the disciples feet. This was a humbling act. So much so that Peter initially refused.
Now look at John 13:15 – 17. Christ points to His example and says that if we (I use we here because of John 17:20) know about His example we should follow it.
Putting that together it reads a lot like Paul’s exhortation in Philippians 2:5 – 30. We are to have the same attitude that Christ did. We empty ourselves as He did. He did because He knew all things were given to Him. They were already His, He did not have to work for them. We have the same thing in Him. Colossians 2:9 – 10 reminds us we are complete in Him. We have all that God is going to give us already and it is a rich, rich, rich inheritance.
So like Christ we lose nothing by humbling ourselves to serve. Our standing with Him and with His Father is impossible to diminish, no matter how far we stoop to serve, or how demeaning the task in which we choose to engage. We cannot be demeaned more than our Lord.
We know, therefore we should follow Him.