Hadith: The example of the one who remembers his Lord and the one who does not remember Him is the like the example of a living and a dead person

عن أبي موسى الأشعري رضي الله عنه عن النبي صلى الله عليه وسلم قال: «مثل الذي يذكر ربه والذي لا يذكره مثل الحي والميت» وفي رواية: «مثل البيت الذي يُذْكَرُ الله فيه، والبيت الذي لا يُذْكَرُ الله فيه، مثل الحيِّ والميِّت».
[صحيح] - [متفق عليه]

Abu Mūsa al-Ash‘ari (may Allah be pleased with him) reported: The Prophet (may Allah's peace and blessings be upon him) said: "The example of the one who remembers his Lord and the one who does not remember Him is like the example of a living and a dead person." The narration in Muslim reads: "The house in which Allah is remembered and the house in which Allah is not remembered are like the living and the dead respectively."
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

Meaning of the Hadīth: Allah, the Almighty, revives the heart of the person who remembers Him, and makes His remembrance easy for him. His similitude is that of a living person because he remembers Allah continuously. On the contrary, the person who does not remember Allah is like a dead person who has ceased to exit. His body is alive, but his heart is dead. This is a parable that people should learn a lesson from. They should be aware that the less a person is heedful of the remembrance of Allah, the more hardened his heart becomes, and may even his heart may die, we seek refuge in Allah from that. Allah, the Almighty, says: {And is the one who was dead and We brought him into life, and gave him light by which walks among people like the one who is in darkness, never coming out therefrom?} [Sūrat al-An‘ām: 22]