The reason for Jesus giving this warning is so that the disciples will not “fall away” when the persecution begins. The verb translated “fall away” in the ESV is σκανδαλίζω. The word can mean brought to a downfall, or “cause to sin.” For example, for a person on a diet, bringing a platter of their favorite dessert is likely going to cause them to sin by breaking their diet and eating the dessert. The food “trips them up” and the fall off the wagon, so to speak.
The word can also have the sense of being offended by someone or something, or to be shocked or angered by something. This may lead to sin as well, so it is sometimes difficult to decide how the word ought to be translated. But in either case, Jesus wants his disciples what they will have to face in the very near future, so that they are not shocked to the point of sin. If they were under the impression that the new few months would lead to a great deal of health and wealth for them personally, they are going to be in for a great shock!
Jesus once again predicts that the disciples will be subjected to persecution. It is clear in these verses that the Jews will be the source of this trouble.
The disciples will be put out of the synagogue. To be thrown out of a synagogue is an indication that the members of the synagogue consider you to be no longer permitted to worship God or study the scripture in that place. This may be the result of some sin, but also for a defection from the truth. We should resist the inclination to read this as “excommunication” in a medieval sense, but in a small Jewish community to be expelled from the synagogue was to be expelled from polite society!
The disciples will be killed. While execution for non-belief is not common in the Jewish world, there are some examples in the book of Acts, certainly Stephen (Acts 7) and James (Acts 12) are examples of this very things
The ones who are doing the persecution think that they are serving God. This is possibly a result of the type of zeal demonstrated by Phineas in Numbers, when he “burned with zeal” and attacked a man who was sinning with a Moabite prostitute at the tabernacle. So too did Elijah “burn with zeal” when he killed the priests of Baal in 1 Kings, or Judas Maccabees when he attached the Greeks after the desecration of the Temple.
Paul’s own persecution of Jewish believers in Jesus as messiah and savior is an illustration of this very persecution. Certainly he worked to silence those who claimed that Jesus had been the Messiah, that he had been raised from the dead and that he was coming back to judge. This is not a matter of a slight difference of opinion, for pre-Christian Paul this was an attack on the heart of Judaism and a completely false accusation against the high priest and the Sanhedrin. For Paul, his actions were exactly the right course to take in the service of God.
The sad truth is that this passage has been badly misunderstood and used as a justification for all kinds of attacks on the Jewish people for centuries at the hand of “good Christian people.” Fredrick Bruner has a stunning commentary on the abuse of Jews in World War II at the hands of people who were a part of the confessional church. It is a sad irony that while many thought they were killing Jews as part of their Christian duty, they were as guilty as those who persecuted the apostles in Acts.
This passage (nor any other in the Bible) advocates any sort of persecution of Jews (or anyone else) because they are “unbelievers.” We can disagree, slightly or completely, with another religion, but as Christians it is not our duty to respond with hate or violent repression.