About ego
In the spiritual sense of the word, ego is the false persona, created by us in rebellion against the beauty and goodness God made in us. Ego clamps down on our loveliest impulses. And it works to suppress and invalidate our most beautiful characteristics -- replacing our love with fear; our natural generosity with selfishness and self-protection; our native strength and passion with cowardice and mediocrity; our beautiful sensitivity with hard-heartedness; our love of rightness with greed; etc.
Ego is the set of ideas, beliefs, and assumptions by which we maintain our sense of separateness from God and all of life. And it is the selfish, self-protective, fearful mentality orientation which accompanies that sense of separation.