When we are materially contaminated, we are called conditioned. False consciousness is exhibited under the impression that I am a product of material nature. This is called false ego.
(Bhagavad-Gita-introduction).

The person in material consciousness is convinced by false ego that he is the doer of everything. He does not know that the mechanism of the body is produced by material nature, which works under the supervision of the Supreme Lord. The materialistic person has no knowledge that ultimately he is under the control of Kṛṣṇa. The person in false egotakes all credit for doing everything independently, and that is the symptom of his nescience.
(Bhagavad-Gita---3:27---purport).

Intelligence is the immediate next—door neighbor of the spirit soul. Lusty intelligence influences the spirit soul to acquire the false ego and identify itself with matter, and thus with the mind and senses. The spirit soul becomes addicted to enjoying the material senses and mistakes this as true happiness.
(Bhagavad-Gita---3:40---purport).

A person in Kṛṣṇa consciousness is always transcendental to the material modes of nature. He has no expectations for the result of the work entrusted to him, because he is above false ego and pride. Still, he is always enthusiastic till the completion of such work. He does not worry about the distress undertaken; he is always enthusiastic. He does not care for success or failure; he is equal in both distress and happiness. Such a worker is situated in the mode of goodness.
(Bhagavad-Gita---18:26---purport).

Material desires are based on the false ego of the living being and are exhibited by his childish and useless activities to conquer the laws of material nature and by his desire to lord it over the resources of the five elements. With such a mentality, one is led to believe in the strength of material science, with its discovery of atomic energy and space travel by mechanical vehicles, and by such tiny advancements in material science the false egoist tries to challenge even the strength of the Supreme Lord, who can finish all man's tiny endeavors in less than a second.
(Srimad Bhagavatam---2:2:19---purport).

The chief function of the false ego is godlessness. When a person forgets his constitutional position as an eternally subordinate part and parcel of the Supreme Personality of Godhead and wants to be happy independently, he functions mainly in two ways. He first attempts to act fruitively for personal gain or sense gratification, and after attempting such fruitive activities for a considerable time, when he is frustrated he becomes a philosophical speculator and thinks himself to be on the same level as God. This false idea of becoming one with the Lord is the last snare of the illusory energy, which traps a living entity into the bondage of forgetfulness under the spell of false ego.
(Srimad Bhagavatam---3:5:31---purport).

The influence of the Supreme Personality of Godhead is felt in the time factor, which causes fear of death due to the false ego of the deluded soul who has contacted material nature.
The living entity's fear of death is due to his false ego of identifying with the body. Everyone is afraid of death. Actually there is no death for the spirit soul, but due to our absorption in the identification of body as self, the fear of death develops.
(Srimad Bhagavatam---3:26:16---translation and purport).

The conditioned soul thinks, "I am this body," but a liberated soul thinks, "I am not this body. I am spirit soul." This "I am" is called ego, or identification of the self. "I am this body" or "Everything in relationship to the body is mine" is called false ego, but when one is self-realized and thinks that he is an eternal servitor of the Supreme Lord, that identification is real ego. One conception is in the darkness of the threefold qualities of material nature—goodness, passion and ignorance—and the other is in the pure state of goodness, called śuddha-sattva or vāsudeva. When we say that we give up our ego, this means that we give up our false ego, but real ego is always present. When one is reflected through the material contamination of the body and mind in false identification, he is in the conditional state, but when he is reflected in the pure stage he is called liberated.
(Srimad Bhagavatam---3:27:13---purport).