What does Luke 8:36 mean?

Pig herders have called people from miles around to see how about two thousand pigs spontaneously ran into the Sea of Galilee and drowned. Matthew says the herdsmen "told everything, especially what had happened to the demon-possessed men" (Matthew 8:33). When the people arrive on the scene, they're astonished that the man who wandered the local graveyard, moaning and cutting his own flesh (Mark 5:5), is sitting "clothed and in his right mind" (Luke 8:35). Pigs are one thing; power over a violent demonic force is quite another. The people want to know more, so the herders explain what they saw (Luke 8:27–35).

We aren't told what, exactly, the pig-herders are saying, but the effect is interesting. The people don't thank Jesus, worship Him, or ask to follow Him. They respond in "great fear" (Luke 8:37). The demons had made the man so powerful, "no one had the strength to subdue him" (Mark 5:4). Except Jesus. That makes Jesus very, very dangerous. So much so that the people beg Him to leave (Mark 5:17).

Contrast the witness of the pig herders to the newly rescued man. He begs Jesus to take him along. Instead, Jesus gives him a commission: "Return to your home, and declare how much God has done for you" (Luke 8:38–39). The man does so. And the next time Jesus comes to the area, He's first met with a group who brings a deaf man for healing (Mark 7:31–37) and then by over four thousand people who come to hear Him teach (Mark 8:1–10). The man who understood the saving power of Jesus was able to turn an entire district from fear to faith.