Short answer
Dhikr (remembering Allah) brings peace to the heart, makes Allah remember you, earns forgiveness and great reward, and protects from Satan. The Prophet ﷺ compared the one who remembers Allah and the one who does not to the living and the dead.
Dhikr is mustahabb at all times, in every state, with or without wudu. The sunnah adhkar after salah and in the morning and evening are a strong sunnah, and the four schools agree on its virtue.
The four schools agree on this.
Explanation
In the Quran:
- Peace of heart: by the remembrance of Allah hearts find rest (13:28).
- Allah remembers you: remember Me, I will remember you (2:152).
- Forgiveness and reward: for men and women who remember Allah often, Allah has prepared forgiveness and a great reward (33:35).
- Greater than other deeds: the remembrance of Allah is greater (29:45).
In the sunnah:
- "The example of the one who remembers his Lord and the one who does not is like the living and the dead." (al-Bukhari)
- Allah says: "I am with My servant when he remembers Me." (al-Bukhari)
- A man asked for one deed to hold onto, and the Prophet ﷺ said: "Keep your tongue moist with the remembrance of Allah." (al-Tirmidhi)
- Specific phrases carry great rewards, such as SubhanAllah wa bihamdihi a hundred times wiping away sins. See the best dhikr.
Benefits people feel: calm in anxiety, patience in hardship, less idle talk, a softer heart and closeness to Allah. Dhikr is also a shield: the morning and evening adhkar protect from harm. See does dhikr help with anxiety.
How to start: the adhkar after salah, the morning and evening adhkar, and a little dhikr while walking or driving. You can do it silently or aloud, with your fingers or beads. See the daily dhikr list, morning and evening adhkar, dhikr without wudu and the tasbih counter.
The evidence
Quran, Surah Ar-Ra'd 13:28
ٱلَّذِينَ ءَامَنُوا۟ وَتَطْمَئِنُّ قُلُوبُهُم بِذِكْرِ ٱللَّهِ ۗ أَلَا بِذِكْرِ ٱللَّهِ تَطْمَئِنُّ ٱلْقُلُوبُ ﴿٢٨﴾
Those who have believed and whose hearts are assured by the remembrance of Allah. Unquestionably, by the remembrance of Allah hearts are assured."
Dhikr brings peace to the heart.
Quran, Surah Al-Baqara 2:152
فَٱذْكُرُونِىٓ أَذْكُرْكُمْ وَٱشْكُرُوا۟ لِى وَلَا تَكْفُرُونِ ﴿١٥٢﴾
So remember Me; I will remember you. And be grateful to Me and do not deny Me.
Allah remembers those who remember Him.
Quran, Surah Al-Ahzaab 33:35
إِنَّ ٱلْمُسْلِمِينَ وَٱلْمُسْلِمَٰتِ وَٱلْمُؤْمِنِينَ وَٱلْمُؤْمِنَٰتِ وَٱلْقَٰنِتِينَ وَٱلْقَٰنِتَٰتِ وَٱلصَّٰدِقِينَ وَٱلصَّٰدِقَٰتِ وَٱلصَّٰبِرِينَ وَٱلصَّٰبِرَٰتِ وَٱلْخَٰشِعِينَ وَٱلْخَٰشِعَٰتِ وَٱلْمُتَصَدِّقِينَ وَٱلْمُتَصَدِّقَٰتِ وَٱلصَّٰٓئِمِينَ وَٱلصَّٰٓئِمَٰتِ وَٱلْحَٰفِظِينَ فُرُوجَهُمْ وَٱلْحَٰفِظَٰتِ وَٱلذَّٰكِرِينَ ٱللَّهَ كَثِيرًۭا وَٱلذَّٰكِرَٰتِ أَعَدَّ ٱللَّهُ لَهُم مَّغْفِرَةًۭ وَأَجْرًا عَظِيمًۭا ﴿٣٥﴾
Indeed, the Muslim men and Muslim women, the believing men and believing women, the obedient men and obedient women, the truthful men and truthful women, the patient men and patient women, the humble men and humble women, the charitable men and charitable women, the fasting men and fasting women, the men who guard their private parts and the women who do so, and the men who remember Allah often and the women who do so - for them Allah has prepared forgiveness and a great reward.
Frequent dhikr earns forgiveness and great reward.
Sahih al-Bukhari 6407
Sahih... مثل الذي يذكر ربه والذي لا يذكر ربه مثل الحي والميت ...
"The example of the one who remembers his Lord and the one who does not is like the living and the dead."
Dhikr gives life to the heart.
Jami' at-Tirmidhi 3375
Grading to be checked... لا يزال لسانك رطبا من ذكر الله ...
"Keep your tongue moist with the remembrance of Allah."
Constant dhikr is a deed to hold onto.
Sahih al-Bukhari 7405
Sahih... أنا عند ظن عبدي بي وأنا معه إذا ذكرني ...
"I am as My servant thinks of Me, and I am with him when he remembers Me."
Allah is with the one who remembers Him.
Where the ruling is recorded
- al-Adhkar (al-Nawawi), Opening chapters on the virtue of dhikr. Collects the ayat and hadith on the merit of remembrance.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.