The answer can be formulated as follows.

Overcoming the Devil Within

The answer can be formulated as follows. If we consider the ego as a manifestation of the devil, then freeing oneself from its influence is achieved primarily through strict obedience to God’s will and constant self-control over one’s actions and thoughts. In one of the teachings it is emphasized that any good impulse can be darkened by an impure thought, which is the fruit of the devil:

"He strives to eradicate every thought, to extinguish or hinder every good intention, and to spoil or transform every good deed into evil. … If you allow the devil to invade your soul in this way, then you are your own 'Herod'! …

How can you be saved from him?

… And for this we find an indication in today’s Gospel. … There lies the salvation from devilish schemes! — In unconditional obedience to God and in keeping His commandments and orders." (source: link txt, page: 1978)

Another text offers practical advice on how not to let the devil (and, accordingly, the ego, taken as a manifestation of the devilish element) seize the soul. It stresses the importance of renouncing thoughts that please Satan and actively chasing them away, for it is through the refusal to yield to temptation that one preserves one’s integrity and purity:

"Do not allow thoughts pleasing to Satan, do not sympathize with them, do not be swayed by their suggestions, and do not consent to them — Satan comes and goes, and eventually, he will recede: … If he takes hold of someone, it is because that person has given themselves over to him as a slave. … Do not entertain evil thoughts and you will forever seal the door of your soul to Satan." (source: link txt, page: 107)

Thus, if the ego is perceived as a manifestation of the devil, then liberation from its influence requires two key approaches: absolute and unconditional obedience to God by following His commandments, and constant vigilant control over one’s own thoughts, where each manifestation of selfish or unkind disposition must be consciously rejected. This not only helps prevent the penetration of devilish influences into one’s soul but also preserves spiritual purity despite the constant threat and treacherous schemes of the enemy.