In the Bible we read passages like this:
You may also buy from among the strangers who sojourn with you and their clans that are with you, who have been born in your land, and they may be your property. You may bequeath them to your sons after you to inherit as a possession forever. You may make slaves of them, but over your brothers the people of Israel you shall not rule, one over another ruthlessly. (Leviticus 25:45-46)
Does this seem like a Godly thing to do, to own a man as a possession? Why is such a passage in the Bible? We'll come back to this passage in a little while. Let's consider firstly that the Law was given for the sake of people living in a fallen world. In a fallen world, people fall on hard times. They cannot afford to own or maintain their home, or to feed their family. The kind of slavery usually referred to in the Bible is that situation where people sell themselves into slavery. And in fact, we do exactly the same thing today. If you have a mortgage on your home you are essentially a “slave” to the bank – a great deal of your income is for them. But you willingly do it because how else are you going to afford your home? These kinds of financial relationships, however, are open to abuse and must be regulated by laws. Many passages in the Law of Moses deal with equity in business, given the fallen world we live in. In a perfect world; (the New Heavens and New Earth), there will still be authority, but we will gladly submit to authority. And there will still be service, but we will gladly serve one another, expecting nothing in return. And we won't be taken advantage of, because those we serve will be eager to reward our service justly.
In Exodus 20, God says:
I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery. (Exodus 20:2)
Delivering Israel from slavery was precisely how God showed His love and mercy towards them. It is evident that God saw the oppression of Israel under slavery in Egypt as evil. That kind of slavery is clearly opposed by God. See how often God reminds them not to oppress others...
You shall treat the stranger who sojourns with you as the native among you, and you shall love him as yourself, for you were strangers in the land of Egypt: I am the LORD your God. (Leviticus 19:34)
You shall not oppress a sojourner. You know the heart of a sojourner, for you were sojourners in the land of Egypt. (Exodus 23:9)
He executes justice for the fatherless and the widow, and loves the sojourner, giving him food and clothing. Love the sojourner, therefore, for you were sojourners in the land of Egypt. (Deuteronomy 10:18-19)
When you gather the grapes of your vineyard, you shall not strip it afterward. It shall be for the sojourner, the fatherless, and the widow. You shall remember that you were a slave in the land of Egypt; therefore I command you to do this. (Deuteronomy 24:21-22)
This is just a handful of verses and we get the point already. Just as God rescued Israel from the oppression of slavery, Israel is to show the same kind of mercy and compassion on the poor and the sojourner; that is, someone who is not an Israelite but is living in the land. They were to “love him as yourself” as the first of those passages reads.
Now, homelessness is a reality for this world, just as much back then as it is now. Look at the passage in Deuteronomy 24, above, for example. God is teaching Israel to deliberately leave some of their harvest for the poor to gather, free of charge. When we think of slavery, we think of oppression. But consider that class of people who would be homeless if it weren't for someone taking them in and giving them work under some kind of arrangement. Slavery doesn't necessarily mean without pay, either. The Law does refer to slaves getting paid in Deuteronomy 15:16. But even if it were without pay, slaves would have been given food and shelter, and that would have been better than nothing. The intention was never to exploit slaves. Consider in this day and age how noble it would be for a man who owns a factory, or some other business, when he can no longer afford to take on any more staff, he opens his doors to the homeless and says, “Whilst I cannot pay you, I will provide you with a meal and you may sleep on the factory premises after hours.” People would praise this man for getting those homeless off the street, teaching them skills, giving them something to do with their hands, and providing for them. Care for the poor is what the Law is teaching.
The Law prevented Hebrew slaves from being kept for more than six years. In the seventh year a slave was to be set free; and not just left to go free but "furnished liberally from out of your flock" (Deuteronomy 15:14). And look also at what this passage goes on to say...
But if he says to you, ‘I will not go out from you,’ because he loves you and your household, since he is well-off with you, then you shall take an awl, and put it through his ear into the door, and he shall be your slave forever. And to your female slave you shall do the same. (Deuteronomy 15:16-17)
What kind of a master-slave relationship do you think God expects from His people if there is the expectation that a slave might say “I love my master, I don't want to leave.”? When the relationship is based on love, as all Godly relationships should be, even a slave can say “I love my master.” In the New Testament book of Philemon, Paul tells a runaway slave to return to his master. He doesn't say "set the slave free", but rather encourages them both to turn their relationship into a Godly one. Authority is given by God to be handled responsibly and to be respected by those under it. And service is our opportunity to express love.
So what about the passage at the start of this post which speaks of “possessing forever” a slave? In the context, it speaks of the Jubilee year when Hebrew slaves were set free. But when the slave is a foreigner, there is no obligation to set the slave free. This is what it means to “possess forever”; though as we've seen clearly, the treatment of that slave should be kind and not intolerable to the slave. But why is there this distinction? Some of the Mosaic Laws were designed primarily to teach Spiritual lessons. I believe there is a Spiritual lesson behind this. The Bible calls those who are saved the “sons of Abraham” (Galatians 3:7). I, for example, am not physically a descendant of Abraham but I am a “spiritual descendant”. So the lesson here is a physical parallel to a Spiritual truth; that those who were physically and literally sons of Abraham find freedom after bondage, but those who are not are slaves forever.
So, brothers, we are not children of the slave but of the free woman. (Galatians 4:31)