Jesus rebukes the storm in the same way He would rebuke a demonic spirit. When God shows up, the devil’s plans get thwarted. As a Christian, you can not be possessed. Christians can be oppressed or obsessed.
Do you find yourself in dark places? In places you cannot escape? Chains can be generational stuff we deal with, not just literal chains. You do a lot of what you do as a result of your upbringing.
Do not play with the demonic. Be careful who you associate with. Bad company corrupts good character.
Jesus went across the sea for one man. If He went to the cross for you, you must be important.