Do not let anyone who delights in false humility and the worship of angels disqualify you for the prize. Such a person goes into great detail about what he has seen, and his unspiritual mind puffs him up with idle notions – Colossians 2:18
This is a warning against basing theology on experience. The person described here claims to have seen something (some translations say “visions”), possibly something supernatural associated with angels, and uses this to puff himself up and gather followers.
But, Paul says such a person is “unspiritual” and full of “idle notions.” What the text literally says is “puffed up by the mind of the flesh of him.” This implies his visions are the product of his flesh, not encounters with God or angels.
One of the most dangerous things we can do as a Christian is base our theology on our experience and second to that in danger level is following those who do that.
Sound teachers teach from the Word of God. They exposit the scriptures. They do not ground their theology in their experience but in God’s revealed word. Faith comes by hearing, not the fantastic tales of those who claim to have been to heaven and back, but the words of Christ (Romans 10:17).
So if you encounter a teacher whose main point is based on his personal experience, things like “a word” he’s received directly from God or a visit from an angel or a trip to heaven, run the other way. He is “unspiritual” and full of “idle notions.”