Among the most alarming signs of a spiritually dead heart is the absence of sorrow or remorse when one disobeys Allah ﷻ. When sins no longer stir regret, and the heart feels no pain in distancing itself from the Divine, it indicates a severe spiritual illness. A living heart responds to sin with a sense of weight, shame, and a longing to return to Allah.

Conversely, a dead heart is indifferent—its sensitivity dulled, its connection severed. This spiritual numbness is dangerous because it removes one from repentance (tawbah), which is the gateway to mercy. 

The cure lies in constant remembrance (dhikr), sincere repentance, and companionship with those whose hearts are alive, until the heart begins to feel again and turn back to its Lord.