Is this a biblical term?
No. The Bible never uses the expression “marine spirits”. People sometimes use the term for spirits they associate with the sea, water, dreams, sexual temptation, or certain recurring troubles. Those ideas may be widespread in some Christian settings, but a familiar spiritual label is not automatically biblical teaching.
The New Testament does speak about the devil, demons, deception, temptation, and spiritual conflict. Paul tells the Christians in Ephesus that their deepest struggle is not against flesh and blood, but against spiritual wickedness. Yet he does not provide a catalogue of demon types, assign spirits to territories, or tell believers to identify an evil spirit behind every difficulty (Ephesians 6:12).
John gives a wise starting point: test what is being taught. A claim should be measured against the truth about Jesus and the teaching of Scripture, rather than accepted because it is dramatic or frightening (1 John 4:1).
Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.
The sea belongs to God
In the Bible, the sea can represent danger, chaos, or forces people cannot control. That makes sense in a world where storms could quickly overwhelm a fishing boat. But the sea is never presented as an independent realm owned by evil. It belongs to the Lord who made it (Psalm 95:5).
Jesus showed this on the Sea of Galilee. When a storm terrified his disciples, he rebuked the wind and commanded the sea to be still. The point was not that they needed to learn the name of a power in the water. They were confronted with Jesus' identity, because even the wind and sea obeyed him (Mark 4:39-41).
So Christians needn't treat oceans, rivers, rain, or ordinary water as spiritually cursed. Creation is good because it comes from God, though the world is also broken by sin and suffering (Genesis 1:31).
And he arose, and rebuked the wind, and said unto the sea, Peace, be still. And the wind ceased, and there was a great calm.
Take evil seriously without panic
Jesus did encounter unclean spirits, and the Bible does not ask anyone to pretend evil is unreal (Luke 4:33-35). Still, Scripture's answer is steady, not sensational. James calls believers to submit themselves to God and resist the devil. The emphasis is on God's nearness and grace, not secret knowledge about dark powers (James 4:7-8).
Paul describes a practical way to stand firm: truth, righteousness, readiness with the gospel of peace, faith, salvation, and God's word. Prayer is part of this life too. These are not fear-filled rituals. They are the ordinary ways Christians keep trusting and obeying God (Ephesians 6:13-17).
If teaching about marine spirits leaves you frightened of water, dreams, other people, or daily life, pause. God has not given his people a spirit of fear. Christ is greater than the evil at work in the world (2 Timothy 1:7; 1 John 4:4).
Keep your attention on Christ
Jesus gave his followers authority over evil spirits, but when they returned excited by that authority, he redirected their joy towards belonging to God (Luke 10:17-20). That is a helpful centre. Christian faith is not about becoming an expert in darkness. It is about knowing, trusting, and following Jesus.
When someone speaks about marine spirits, ask a few simple questions. Does this claim come clearly from Scripture? Does it draw me towards truth, prayer, peace, and faithful living? Or does it feed fear and speculation? Read the relevant passages yourself, and if you are concerned, speak with a mature, trustworthy Christian leader who will help you keep Christ at the centre.
Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.