Have you ever locked yourself out of your house? You usually notice this fact just after the front door goes "click" while locking closed. But it does happen that you return home and find you have left your house keys inside.. Now, picture for a moment that one of your children is at home—watching TV. They don't hear you knock—the TV is too loud—but they hear the tiny scratching sound of you coming in through the window. (Selective hearing seems to be a prevalent disease). Just what are you going to say to that kid?
Christ has something of a similar message here for the Christian. He makes it very, very clear that he is returning—in power and glory. He makes it clear that this will be at a time which is unexpected. And he makes it clear that he has told you how to be ready.
Dressed ready for service
This is the "physical" side of Christianity. All the aspects of charitable service are included in this. We are to be ready to do those things. How? The easiest way is to be doing them continually. Then it doesn't matter when he comes; your works will be in progress, and you will be ready.
This is the "contemplative" side of Christianity—including such things as prayer, meditation and Scripture reading. Without such things, your lamp is out, and you can't see where you're going. Not much sense in being dressed for service if you can't see your way to it, is there? Again, the secret is simple: the habit of regular prayer; the practice of continually meditating on the words of our Lord and reading the Scripture will keep your lamp lit.
Jesus gives the picture of returning in the second or third watch—the middle of the night. How are we to be ready? Take a hint from St. Francis of Assisi. He was gardening when he was asked what he would do if he found out the Lord was returning that afternoon. "Finish my gardening," he said. He lived his life in such a way that it did not matter when the Lord returned; he was doing what he had been appointed to do.
There is one unusual point here: the master will serve the servants. When our Lord returns it will be a great and glorious day for those who are ready, and their rejoicing will be great. He will be unexpected—but they will be ready. Will you?