First, the slave is to “Serve wholeheartedly.” As a Christian, you (the slave) have joy in your heart because Jesus Christ is your Lord and Savior, therefore your attitude is different. Your master is most likely a non-believer, but still you do your best to be pleasing to your master by putting forth every effort possible to do the work as is desired by the master. At times it will be difficult knowing the master may use his profit to worship an idol. But on the other hand, by doing your best, the master may put you in charge over others and even down the road, the master may give you freedom. Even better by your actions be able to lead your master to Jesus Christ. The situation could be that your master also is a Christian. This does not mean your master is to automatically free you. Whatever type of master you (the slave) has, you are to serve willingly with your whole heart. Making the application to an employee today, you are to put your total effort into the responsibility you have been given. An example of this is; an employee was doing piece work in a factory and doing it at a faster rate than others, when he had other employees come to him and to tell him to slow down because they knew they would have to meet his rate. These other employees were not serving wholeheartedly.
The reason is “because you know that the Lord will reward everyone for whatever good he does.” You may have the worst master or boss who treats you like dirt and you still do good, the Lord Jesus Christ will reward you. The master is not the only one who keeps records. There are in heaven books which keep record of everything you have ever done or said, therefore, you will receive your just reward. Also, remember when you are in Christ, your sins are washed away for they have been covered by the blood of Jesus Christ.
Paul is saying, “whether he is slave or free,” it does not matter when it comes to their relationship with Jesus Christ. Paul puts it this way in Galatians 3:28, “There is neither Jew nor Greek, slave nor free, male nor female, for you are all one in Christ Jesus.” Therefore, it does not make any different what your background is, where you came from, or your social status, when Jesus Christ is your Lord and Savior, you are one in Him.
THINK CAREFULLY IF YOU ARE WHOLEHEARTEDLY WORKING FOR YOUR EMPLOYER!!!