What does Mark 5:19 mean?
This is not the only time a recipient of Jesus' kindness wishes to stay with Him. In Luke 17:11–19, Jesus heals ten men with infectious skin diseases, and one returns to thank Him. Some women whom Jesus had healed support Him when He comes through their towns, most notably Mary Magdalene (Luke 8:1–3). Peter follows Jesus after the healing of his mother-in-law (Mark 1:29–31).Many others offer to follow Jesus but are rejected, for various reasons. Jesus tells the rich young ruler to sell all his possessions as proof he values God more than wealth, and the man declines (Mark 10:17–22). In Matthew 8:18–22, Jesus discourages a scribe and a casual disciple from following Him, telling them they will have to abandon both comforts and family.
The incident recorded here may be the first time Jesus leaves a prospective follower behind, not because he was unworthy, but because God has prepared a greater purpose for him. The man certainly would have benefitted from traveling with Jesus and learning from Him. But the Kingdom of God is better served by his witness to his friends and family. Jesus not only heals him, He allows the man to return and reconcile with his family. And as a Gentile with no pre-conceived notions about the Messiah, he can spread the pure news that God has shown mercy and saved him.
Jesus doesn't need all of us to go to Bible college, or to become missionaries and pastors. Some Christians can have a greater impact bearing witness to Christ by evangelizing right where we are. This man's witness had a part in paving the way for the gospel of salvation that spread through Gentile communities after Jesus' ascension.