Our Lord Jesus had just rendered the lowly service of washing the dirty feet of men. He then says, "If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet." And then He defines happiness.
The most contradictory thing in the world is an unhappy Christian. Why would there be such a thing? I believe our Lord teaches us here the cause of unhappiness in one who truly knows Him. What is it? The refusal to wash the dirty feet of his brethren. Do you wash their feet? That is, if they have need, do you refuse to supply that need? Do you go out of your way to make their lives a little easier?
"If ye know these things." Why, you do know these things, do you not? You know if you are bound in taking care of self and ignore the dirty feet of others, that you cannot be happy, for the Spirit of Christ will not allow it.
Does the church have a need? Supply it, and find the happy notes sounding in your heart. Give your most precious possession for the aid of others in the church. Mary gave the very costly ointment for His feet, and the house was filled with the odour of the ointment. You can be sure Mary found happiness in that. And if we do for any of His, it is the same as doing unto Him (Matt. 25:40).
Are you unhappy? Get up off your nest egg of ease and go to some trouble for the church. Wash someone's feet and when you have finished, look for other dirty feet to wash and you won't have time to be unhappy. Your "happiness" is not the most important thing anyway. The glory of God in the Lord Jesus Christ is the supreme objective in this world. We were made for that end, and if a person truly knows Him, and strives to glorify the magnificent God, then included in that is the washing of feet.
Lord, give us more feet to wash, and give us the eyes to always be on the lookout for dirty feet among the saints of God. None of them ought to ever have dirty feet as long as we are around.