What does Matthew 8:34 mean?

A group of Gentiles who have been tending to pigs came running into town with quite a story to tell. A stranger arrived on shore in a boat with several other men. The stranger got out and the two demon-possessed men who lived in the tombs came out and talked to him. Then the stranger apparently sent the demons from the men into the 2,000 pigs they had been tending. The pigs went crazy and immediately rushed into the sea and were drowned (Mark 5:13; Matthew 8:28–31).

It's no wonder the whole town came out to meet Jesus and hear about what had happened. We know from Mark and Luke that when they got there, they found at least one of the formerly demon-possessed men "sitting at the feet of Jesus, clothed and in his right mind, and [the townspeople] were afraid" (Luke 8:35).

Instead of being awed by Jesus' power and drawn to Him, the Gentiles were afraid. They were intimidated by power that could free men who'd suffered for so long under the violent oppression of demons. The disciples may have understood that fear. Mark reported that when Jesus calmed a deadly storm with a single command earlier in the day, they too had been "filled with great fear" (Mark 4:41). They were likely angry, as well, seeing so many valuable animals lost—but when faced by miraculous power, it's reasonable to think fear would override thoughts of revenge.

The difference between the disciples and the Gentiles from that region is that the disciples didn't leave Jesus. They learned to trust Him more. The Gentiles, afraid or not, ask Him to leave. Not only were they afraid of Him and His power, His action had cost someone 2,000 head of pigs. That was a lot of money.

Mark tells us that at least one of the men wanted to go with Jesus and the disciples in the boat as they were leaving. Jesus said no. He told the man to "Go home to your friends and tell them how much the Lord has done for you, and how he has had mercy on you." The man did exactly that (Mark 5:19–20).