What does Acts 5:26 mean?

After the chief priests discovered the apostles preaching in the temple courtyard, they arrested them and placed them in a public prison (Acts 5:17–18). This prison is apparently not terribly close to the meeting place of the Sanhedrin.

The "fear of the people" is a common theme because the political situation in Jerusalem was in a delicate balance. The city and the district of Judea were ruled by a Roman procurator, Pilate. The authorities in Rome knew of his vicious and violent ways. Pilate knew that if he didn't want to be relieved of duty, he needed to control the unwieldy Jews without inciting a riot.

The Sanhedrin was primarily made of men from two different Jewish sects. The majority Sadducees followed the Mosaic law as written and didn't mind the presence of the Romans too much. To a large extent, the Romans supported the priesthood—most of whom were Sadducees—and Roman presence was beneficial for the economy in expanding trade opportunity. The Pharisees were so devoted to the Mosaic law they added more laws, intended to help them better keep the actual Law. Although they were the minority party in the Sanhedrin, they had a greater influence over the populace.

Outside the council were the Zealots. They hated the Romans and wanted them gone, and they were willing to start an insurrection if that's what it took. The land had already seen several insurrections pop up, and with Jesus' triumphal entry, many were afraid He was about to start another one. Fortunately, so the Sanhedrin thinks, Jesus is dead. Unfortunately, His followers won't go away or stop talking about Him.

One problem is that even if Jesus is dead, the people still like Him. He healed them, spoke kindly to them, and publicly embarrassed the Sadducees (Mark 12:18–27), the scribes (Mark 12:38–40), and especially the Pharisees (Matthew 23:1–36). In addition, how else could the apostles have escaped if not with help from the people? Divine intervention is too horrible to contemplate—given what it suggests about the serious error Israel's leaders have made—although Gamaliel dares, just a bit (Acts 5:38–39). No, they must have had human help; five thousand men, with more coming daily, is a good start for an army (Acts 4:4).