“Our preacher surely is caustic sometimes,” one member said to another. “He really has a penchant for making me angry.”
Have you ever heard a statement like that? It is more common where the truth is taught on Sunday than where the high point in a sermon is the punchline of a joke.
Jesus said some things that were (and still are) hard for people to hear. His words bristled in the ears of many because he taught the eternal truth of God’s word, and those words stung in the ears of those who believed the “conventional wisdom” of the times.
In John 8:34, Jesus said something very hard for his listeners, but they needed to hear it in preparation for something even harder a few verses later. This is my translation of that verse: “Indeed, truthfully I tell you, whoever keeps on committing sin is sin’s slave.”
One of my college professors was a preacher in East Africa. People there told him how their relatives had been taken from them to become slaves in America. He often spoke of those horrors with tears.
F.F. Bruce wrote, “There is another kind of slavery. Sin is a slave-master, and it is possible even for people who think of themselves as free to be enslaved by sin.”
The word, “commit” in the King James Version of this verse is in the present tense in the language of the New Testament. It carries with it the force of continuous action. A person who is a slave to sin doesn’t just commit one sin; he keeps on committing them. Just as a heroin addict is a slave to the drug, sinners are tied to sin as a slave.
Do you think it was easy for the Jews Jesus addressed to hear they were sinners? Well, it still isn’t even now. But there is a happy note here if we look for it.
For those enslaved to sin, who belong to it, there is the possibility of freedom. The sinner can be set free! His freedom, however, comes from only one: the son.
Jesus said, “And the servant abideth not in the house forever: but, the son abideth ever. If the son therefore shall make you free, ye shall be free indeed,” (John 8:35-36 KJV). Slaves could be sold quickly. They may be in one household and then become a slave somewhere else. Only the son of the homeowner stayed in the house. When the Jewish son attained a certain age, he received authority to free any slave.
Jesus is the son of God who can free sin’s slaves through obedience to the gospel. The freedom he offers is like no other freedom in the world because it means being liberated from the clutches of the worst slave-master ever: sin.
In John 8:44, the Jews would hear the hardest words. Jesus said, “You are of your father the devil.” They needed to know who was holding their chains. Every one of us need to know that!
 F.F. Bruce The Gospel of John, pp. 197