What does Mark 5:6 mean?

Upon meeting Jesus, demons seem to have two compulsions: to approach Him and to show submission (Mark 1:23–24; 3:11). When these demons sense Jesus' presence, probably before the disciples had landed the boat since they greet Jesus "immediately" (Mark 5:2), they impel the possessed man to run to Him, despite the fear of real danger to themselves (Mark 5:7).

"Fell down before" comes from the Greek root word proskuneo, which means to revere, often by kneeling or prostrating oneself in respect or supplication. This is not necessarily a positive act, but one that recognizes someone in a superior position. The same word is used of the mocking guards who struck Jesus before the crucifixion (Mark 15:19). It is taken from the image of a dog licking its master's hand. In contrast, the synagogue leader (Mark 5:22) and the woman with the issue of blood (Mark 5:33) will respectfully and willingly fall before Jesus, even without knowing His identity as the Son of God.

There is no reason to think the man, himself, knows Jesus' true identity. It is the demons who control his body, telling him to run and fall. Evil spirits can control movements and speech, but they have no power over God, whether the Father, Jesus, or the Holy Spirit. This means that born-again, saved Christians can't be possessed. Evil spirits lack the authority or desire to be where Jesus is. They may still seek to attack and cause problems for believers (Ephesians 6:12) and tempt believers, just as Satan tempted Jesus (Matthew 4:1–10). However, evil spirits must submit to God. If we are indwelt by the Holy Spirit, we cannot be possessed by demons.