The Faithful and Wise Servant

Luke 12:35-40 "Let your loins be girded and your lamps burning. Be like men watching for their lord, when he returns from the marriage feast; that, when he comes and knocks, they may immediately open to him. Blessed are those servants, whom the lord will find watching when he comes. Most assuredly I tell you, that he will dress himself, and make them recline, and will come and serve them. They will be blessed if he comes in the second or third watch, and finds them so. But know this, that if the master of the house had known in what hour the thief was coming, he would have watched, and not allowed his house to be broken into. Therefore be ready also, for the Son of Man is coming in an hour that you don’t expect him."
Serving Christ is not optional in the Christian life. Not that salvation is performance-based. We neither gain nor lose salvation based upon our performance. But rather we reveal the quality of our faith by our behavior. If we truly believe that Jesus is Lord, then we will treat him that way. By faith we take on the role of servants, for that is what we are. The role of servant today is better illustrated by a position in the military, as opposed to simply being an employee. It's a 24 hour job and at any time you may face judgement from your commanding officer. You may even be asked to give up your own life.
Employees expect to get paid for their work. But God is not obligated to reward us for good service. For we are slaves to Christ, bought with the price of his blood. We serve because that is our purpose given to us by the Creator. Nonetheless, because He is gracious, he does indeed reward us for our service. But it is not impersonal like paying a salary, but rather out of genuine appreciation for our services. There are those who have the mentality of "What do I get out of it?" They only serve if they see something in it for them. Jesus does encourage such people to serve by pointing out these rewards, but as one matures in Christ, service is seen more as a priviledge rather than simply a means to personal gain.
The illustration of the thief may seem quite in contrast to the master returning. But what he is trying to get at is the element of surprise. It is not that Jesus comes to steal something. There are those who think that Jesus tip-toes in through the window to secretly rapture believers away. But this doens't fit the context. For then the believers would welcome such a thief in to be raptured away. Thieves don't generally break in to steal the owner of the house. And the servants are put in the role of the owner by proxy. The thief in the night illustration is not necessarily one of secretiveness, but one of surprise. Jesus' return is spoken in the New Testament as a single dramatic event, which will not be in secret.