"Moreover, brethren, I declare unto you the gospel... By which also ye are saved... unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures" (1 Corinthians 15:1-4)

"But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat? And will not rather say unto him, Make ready wherewith I may sup, and gird thyself, and serve me, till I have eaten and drunken; and afterward thou shalt eat and drink? Doth he thank that servant because he did the things that were commanded him? I trow not. So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do" (Luke 17:7-10).

The Greek word for servant here is doulos, which means a purchased slave, a bond slave. He had no legal rights. He was required to do whatever his master demanded. We see the meaning in Matthew 8:9. The centurion said, "I say to ... my servant, Do this, and he doeth it" (Mat. 8:9). 

In Roman Empire of Paul's day, as many as 35% of the people were slaves. They could be sold and bought in slave markets in major cities. Some were purchased from pirates. Some poor people sold themselves into slavery, and a father could sell his own children into slavery to pay his debts. There were homegrown slaves, which were children born of slaves, who thus became the property of their owners. Most, though, were obtained as war bounty when Rome's legions conquered people in far-flung places. For example, after Rome destroyed the Jewish Temple in AD 70, more than a million Jews were killed or sold as slaves. In the Roman Empire, a master could treat the slave as he pleased, even unto death. Slaves had no rights. They were considered property and could be sold, beaten, tortured, castrated, prostituted, raped, and killed at the will of their owners. 

Many slaves were worked to death under cruel conditions. Consider the Egyptian mines. "Egypt's gold and quicksilver mines were worked by slaves, criminals and prisoners of war, including women, elderly men and children. Young men hacked the quartz loose. Older men broke the quartz into fragments. Children dragged the quartz to the grinders, powered by women who like others worked without rest, walking in circles and pushing levers that rotated a shaft. According to the Greek writer Agatharchides, in the mid-100s BCE, relief came only with death, which these miners welcomed" ("Privilege, Poverty and Failed Revolutions," Macrohistory and World Timeline, http://www.fsmitha.com). This description refers to the time of the Greek Empire, but nothing of significance changed under the Romans.

Paul called himself the Lord's bond slave (Rom. 1:1; Phil. 1:1; Tit. 1:1). So did James (Jam. 1:1), Peter (2 Pet. 1:1), and Jude (Jude 1:1). This refers to being purchased by Christ from the slave market of sin. Romans 6:17 says "ye were the servants [doulos] of sin," but Christ has made us free and purchased us unto Himself by His blood. He became a doulos that He might redeem us (Phil. 2:7). 

The born again believer is many things before God. He is an adopted child of God (Gal. 3:26), an heir of Christ (Gal. 4:7), a member of Christ's body (Eph. 5:30), Christ's friend (Jn. 15:14), but also Christ's bond servant. Even in the new heaven and the new earth, the Lord's servants [doulos] will serve Him (Rev. 22:3).

Consider some lessons from Christ's account of the unworthy servant. 

In this parable, Christ is teaching about humility. In the previous verse He had taught the disciples about the power of effectual faith. Now He is warning them not to become puffed up by any success they might achieve in the Christian life and ministry or any position they might attain.

1. The servant of the Lord must be ready to do everything God asks of him. 

2. The servant of the Lord must die to his own plans and appetites (Lk. 17:8).

3. The servant of the Lord must serve the Lord with a good attitude without recognition or tokens of appreciation (Lk. 17:9-10). We naturally want to receive recognition and thanks for our service, but a slave typically didn't get that, and the bondservant of the Lord must not look for that or become discouraged when he doesn't get it. "In a sense, we are not needed at all. Service is a rare privilege. The Lord could have dispensed with it altogether had He so decided. What a blow to our spiritual pride" (John Phillips).

This is a very helpful truth in all areas of the Christian life. It is helpful for service. I must be humble and not try to exalt myself and push myself into positions of ministry. If I am not chosen for something, I am to have the attitude of a doulos and not be offended. It is helpful for wives. The wife must submit to her husband as the Lord's doulos. She is serving the Lord by serving her husband. This truth is helpful for church members, who are taught to obey their leaders (Heb. 13:17). We do this not unto man, but unto the Lord, remembering that we are His doulos. This truth is helpful to workers. Paul says, "Servants, [doulos] obey in all things your masters according to the flesh; not with eyeservice, as menpleasers; but in singleness of heart, fearing God" (Col. 3:22). The believer serves his boss well because he is actually serving his heavenly Master as a doulos.