The hearts of this nation are fattened, and their ears are heavy, and their eyes are sealed (Isaiah 6:10).
Some people's conduct may be exemplary in every way, yet they lack a deep emotional relationship with God. They may even have an intellectual awareness of the infinite greatness of God, yet they may fail to experience the sense of reverence that such an awareness should evoke. They may firmly believe that God is their Provider and Protector, yet fail to love Him and be devoted to Him. This insensitivity of the heart and dullness of the senses, states Rabbi Schneur Zalman in Tanya, is due to an insulating barrier with which the yetzer hara has enveloped the thought processes of an individual. Finding itself unable to seduce a person into frank transgressions of the Divine will, the yetzer hara does the next best thing for its purpose. It renders him insensitive in his relationship to God, even when he goes through the motions of performing the commandments. Since the person is technically complying with the Divine will, he may not recognize that his insensitivity is keeping him distant from God.
Drastic measures may be required to overcome this insensitivity and penetrate its shell of insulation. An individual may need a crisis to shatter his ego and thereby overwhelm the yetzer hara. But such a course carries with it the danger of falling into a mood of dejection, which would drain the person's energy and paralyze his functioning. That would hand the yetzer hara a triumph. Conversely, a carefully controlled dismantling of the ego, with proper and competent guidance, can free the individual from the constrictive shell, allow him to feel a closeness to God, and rebuild his healthy ego.