If nihilism can be oversimplified as having an attitude of “I don’t care,” then acedia can be summed up as meaning, “I don’t care that I don’t care.” Acedia is one of the infamous seven deadly sins. In Judaism, it is akin to the Chassidic concept of one’s own “inner Amalek.”
Amalek is the enemy of Israel in every age. Amalek, as recorded in Torah, attacked the stragglers, who were to the rear of the procession of the Israelites, as they marched in formation from place to place, encampment to encampment in the Sinai Desert.
The concept of Amalek, on an internalized level, may manifest as doubt about one’s belief, and the subsequent “coolness,” and lack of enthusiasm one feel towards his or her religious path.
Many disadvantageous conditions of the soul have the ability to “fly under the radar,” so to speak, going unnoticed by an individual, unless time is spent examining the inner dimensions of life. In modernity, we are too focused on image, keeping busy, and entertaining ourselves. Yet, by maintaining our focus on the external, we neglect the internal dimension of the soul.
“Above all that thou guardest keep thy heart; for out of it are the issues of life.” – Proverbs 4:23, JPS 1917 Tanach