1 Corinthians 15:58, ESV
Therefore, my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord your labor is not in vain”

This is about the Kingdom of God. This is about SALVATION. This is about God inviting sinners into fellowship through His Son Jesus Christ.

Mark 5:1-20 is the most detailed description of a demon-possessed man we have in the Bible. It is the classic profile of demonic possession.