"The Two Possessed Men of Gerasa"

The three passages that describe the incident with the demoniacs in the country of the Gerasenes, also called Gadarenes, are Matthew 8:28-34, Mark 5:1-20, and Luke 8:26-39. The Matthew account mentions two demon-possessed men, while Mark and Luke only mention one. 

The timing of the event in all three accounts—immediately following the calming of the storm on the sea of Galilee—as well as other similarities (living in the tombs, the ferocity of the demoniac, the conversation with the demons, the driving of them into the pigs, the drowning of the herd, etc.) all give credence to Matthew, Mark, and Luke all describing the same event. But was there was one demoniac or two.

Matthew tells us there were two demoniacs, while Mark and Luke only mention one of the two. It is unclear why they chose to mention only one, but that does not negate the possibility of a second demoniac being present. Mark and Luke do not say there was “only one” demon-possessed man. They simply state that one of the two met Jesus and spoke to Him. For whatever reason, Matthew simply gives us more information than Mark and Luke.