With regard to audience, it is clear from the verses prior that Jesus is speaking directly to his disciples and students:
The apostles said to the Lord, "Increase our faith!" (Luke 17:5)After which Jesus discussed faith, in Luke 17:6.
So Jesus goes from discussing faith to discussing this analogy about the servants and master. What is the connection?
In his discussion of faith, Jesus talks about their being able to tell a mulberry tree to be uprooted and planted in the sea with just a small amount of faith. As we discussed with this verse, Jesus is not speaking about getting some great power and ability: It is speaking of becoming dependent upon the Supreme Being. This dependency that Jesus is discussing is the same type of dependency that a servant would have upon his master.
Having servants was part of the society then
We must remember that during the time when Jesus walked the earth, having servants was common. Practically every wealthy household had multiple servants, who did the chores, cooked, cleaned the house, took care of the crops and so forth.
By today's standards, many of these workers would be considered slaves - or at least indentured servants. The non-Jewish lower class at that time often held positions of menial service in households and farms. If a person could not pay a debt, they were often forced into servitude in order to pay off their debt. This is basically an indentured servant. Once the servant worked off their debt they were theoretically free to leave the household.
Often the servant would not leave, however. This is because during their indentured service, the servant would often come to depend upon the household for their survival. They were fed and housed and in return performed their service.
Today in most affluent countries, slavery is illegal. To some degree, however, indentured servitude still continues in some cultures.
Even in the Western world, many households do have nannies, cooks, house cleaners and so forth. These are typically not considered indentured servants because they have the freedom to quit and work elsewhere at any time. But they do get paid for their service.
And of course, many corporations employ workers who tend fields, do manufacturing, office work and so forth. Certainly, these workers are also not considered indentured servants - because they too have the freedom to quit their job and work elsewhere.
Nevertheless, all of these types of workers - whether slaves, indentured servants, household employees or corporation employees - typically still come to depend upon their employer for their survival. Sure, many of them could quit, but depending upon their situation and the job market, quitting their job might mean losing their home and not being able to put food on the table - at least until they find a new job.
Thus there is still a dependence or reliance upon the employer or company even to this day among many workers.
This is what Jesus is discussing here, as it relates to our relationship with the Supreme Being. The relationship between the worker and employer or servant and master: The worker and servant are dependent upon their employer or master.
Such is the consciousness of one who wants to be one of God's loving servants: We must become dependent upon God.
You see, the precise working arrangement between the servant and the master in Jesus' analogy is not the point: Because servants and at least indentured slavery was quite common, Jesus could utilize this relationship to illustrate a point to his disciples and students.
The Supreme Being doesn't want slaves anyway. He gives each of us the freedom to choose whether or not we want to love and serve Him. So this is not the point.
Yet being God's servant is still our natural position. Those of us who rebel and try to escape our position as one of His loving servants end up serving the Supreme Being indirectly anyway - in the form of His physical universe and the various roles and situations that exist here. We serve our families, our bosses, our fans - even our bodies. We have to work hard to feed our body and keep it healthy: We are thus servants of our physical bodies - and those who control the fate of our physical bodies.
So we can never really escape our true position as being one of God's servants. This was His purpose for creating us: To help Him enjoy. And as long as we are operating within our position as one of His servants we become fulfilled. When we decide to serve God, we are fulfilling our actual role and position.
God doesn't need our service
It is not as if He really needs anything from us. He is God after all. Rather, what He enjoys most is the exchange of love: He enjoys the loving exchanges that He has with those of His children who choose to love and serve Him voluntarily. This was expressed by the Supreme Being as He described His relationship with Jesus:
Then a cloud formed and enveloped them. A voice came out of the cloud: “This is my beloved Servant – listen to him!” (Mark 9:7 DT)The Supreme Being expressed not only that Jesus was His servant - but that He loved Jesus. This indicates a relationship. A relationship of mutual love.
Jesus indicates his reciprocation of this loving relationship:
"The One who sent me is with me; He has not left me alone, for I always do what pleases Him.” (John 8:29)Jesus also communicates clearly that in this loving relationship, he is also completely dependent upon the Supreme Being:
"By myself I can do nothing; I judge only as I hear, and my judgment is just, for I seek not to please myself but Him who sent me." (John 5:30)This is the critical situation that Jesus is trying to teach his disciples and students to embrace: Not only their role as servant - but their position as being completely dependent upon God.
This is the same dependent and subservient position that Jesus describes in his parable about the master and the servants. While a kind master might certainly thank the servant, the servants are not waiting to be thanked. This would especially be the case if the servitude is indentured - common then as described above.
In such a dependent and subservient role, the servant would not be thinking they would be thanked. Nor would they be expecting it. This goes for employees of a corporation or household today. While some are thanked now and again, mostly the worker just does their job.
Jesus then extends this analogy to the role and consciousness that he wants his disciples and students to have regarding their devotional service to God:
"So you also, when you have done everything you were told to do, should say, 'We are unworthy servants; we have only done our duty.'"Certainly, the Supreme Being does appreciate the voluntary service of those who love Him. This is not the point, however. Jesus is speaking of the attitude his disciples and students should have from their side of the relationship - that they should not be feeling worthy or expecting a 'thank you' from God for their service.
Nor should they be expecting any kind of reward.
Most of us are feeling pretty worthy. We might do a small amount of service and suddenly we are thinking we are darn right worthy. Not only do we expect a return for our pittance of service, but we think we have done such a great thing that we want others to respect us for it. This is quite the opposite consciousness that Jesus is teaching his students with regard to feeling worthy of being respected, thanked or given some other reward.
This, of course, is the clear message to those institutions that compensate their pastors and priests for their theoretical service. Such payments of salaries or houses or anything else in return for their service means that service is not necessarily being done in order to please God. At least to some degree, the service is being done in exchange for payment.
This makes that type of service tainted - and thus cannot be trusted as true service to the Supreme Being.
Jesus is clear with his students that their focus should be upon service - without any expectation of reward - as he illustrates by his own example:
"For I have come down from heaven not to do my will but to do the will of Him who sent me." (John 6:38)Any of us can offer service to the Supreme Being - anyplace and anytime - by praising God's Holy Names. This form of service has been professed throughout the Bible. See the evidence here.