This video teaching taken from, "A Course in Miracles".
The ego is a term used to identify the part of the mind that believes the SELF to be the body, with its mind being the brain.
In the course, Jesus teaches that we should consider the self to be the mind, a spirit because God's spirit dwells in our minds. The Holy Spirit, Thought Adjuster/Spirit Monitor, and Infinite Intelligence are names given for the fragment of God's spirit in our minds.
These teachings declare that, you/we are not the body, therefore YOU/WE, the personality of our minds are not the ego. You/we are not, first, because the spirit in our minds is immortal, eternal and all knowing. It is our guide back to our spirit reality, while the ego only associates with the body as its identity believing it's a material/physical temporary existence, with a soul threatened with condemnation, annihilation or eternal suffering, if believing there's a soul life to be judged for the behavior/deeds of the body.
Everything in this world supports self is body, weak, sickly, and vulnerable; needing supplementation of magical materials for healing, strength, and longevity; and most of all, protection from other bodies and nature.
As long as the mind believes it is the body, the mind lives a fearful existence because the ego knows the body and itself is temporary and sees this world inundated with dangers. We're told this could only happen in dreams.
In this dream, the ego is always concerned with the world, comparing ego to other egos. It feels separate and sees itself different from the other, and because the ego identifies with the body as itself, it has its own biases, desires and needs that it focuses on.
Mind believing self is the body is influenced by believing the body is vulnerable, therefore always insecure with self, alone, believing it requires constant attention and protection from harm, whether physical or psychical.
You are not your body, therefore you are not your ego.
It is taught that you/we are the mind, spirit beings created intelligent energy personalities with free-will to create realities and experience them in forms, which are always illusions. Our spirit is God's fragmented spirit given to our minds creating us the Children/Sons of God; powerful and immortal in eternity, to create as was created for.