“Return to your own house, and tell what great things God has done for you.” And he went his way and proclaimed throughout the whole city what great things Jesus had done for him.
Luke 8:39 (NKJV)
A man possessed by several demons could not be controlled. He lived naked in the tombs. The people of his village could no longer stand him because of his actions, guided by demons. Seeing Jesus arrive, it is not the man but the demons, out of fear, who beg Jesus not to torment them. They knew who He was, the son of the living God. The demons beg Jesus not to send them into the abyss but rather into the herd of pigs that were there. Even the pigs could not accommodate them in their bodies, so they threw themselves into the lake.
It must be understood that no demon can possess a person, even an animal, without God's permission. All the more reason to believe that they cannot attack us directly, because we have God on our side. This also means that if a demon does not occupy a body, its place is in the abyss. This is why demons always look for a weak soul to make their home. Satan always chooses temptation to keep us away from God to better control us.
The most important part of the passage, the man once healed wanted to follow Jesus to become one of his disciples. But Jesus refused, ordering him to go and proclaim all that God had done for him. For Jesus, the testimony of the man's healing was far more important for the whole city than following Him. So there are two things to consider. First, whatever the circumstances of our lives, God is aware of them and He will intervene in His time. Second, God's intervention in our lives must always serve as a testimony to others. This is what makes his glory shine.
I would suggest reading the entire passage (Verse 26 to 39) to better understand what I want to teach here.