Short answer
Yes. Mocking Allah, His verses, His messengers or a clear part of the religion, such as salah or hijab, is kufr (disbelief) even if said as a joke. Laughing at a person for how badly he practises is a sin but not kufr. Whoever slipped into mocking the religion should repent and renew their faith.
Ridiculing Allah, the Quran, a prophet, an angel or any clearly established ruling of the religion is kufr, whether serious or joking. The person must repent and renew the shahada, and the Hanafi muftis also advise renewing the nikah as a precaution. Mocking a Muslim's personal behaviour is haram but not kufr.
The four schools agree on this.
Explanation
The Quran tells of hypocrites who mocked the Prophet ﷺ and his Companions, then said, 'We were only chatting and joking.' Allah answered: 'Is it Allah and His verses and His Messenger that you were mocking? Make no excuse; you have disbelieved after your belief.' So 'it was just a joke' does not excuse mocking the religion itself.
The Prophet ﷺ also warned that a person may say a word that angers Allah without thinking much of it, and it drops him into Hell. Faith is respect for Allah and what He revealed. Mocking it cancels that respect.
The scholars separate two things:
- Mocking the religion: jokes that make fun of Allah, the Quran, the Prophet ﷺ, the angels, Paradise and Hell, the prayer, the beard as a sunnah, or hijab as a command. This is kufr.
- Mocking people: laughing at an imam's accent, a relative who prays very fast, or a friend's bad Arabic. This is a sin (see insults and bad language) but it is not kufr, as long as the target is the person and not the religion.
If someone said such words, the way back is open. Repent sincerely, say the shahada again, and avoid that kind of humour. The Hanafi books advise a married person to renew the nikah as a precaution. Judging that a particular person has left Islam is for a qualified mufti, not for friends or social media. When others mock the religion in front of you, the Quran says not to sit with them until they change the subject.
The four schools agree on the principle.
Ask a mufti about your own case. This answer explains the general ruling. When the details of your situation matter, as they do here, ask a qualified mufti and give them the full facts. Where to ask a scholar.
The evidence
Quran, Surah At-Tawba 9:65-66
وَلَئِن سَأَلْتَهُمْ لَيَقُولُنَّ إِنَّمَا كُنَّا نَخُوضُ وَنَلْعَبُ ۚ قُلْ أَبِٱللَّهِ وَءَايَٰتِهِۦ وَرَسُولِهِۦ كُنتُمْ تَسْتَهْزِءُونَ ﴿٦٥﴾ لَا تَعْتَذِرُوا۟ قَدْ كَفَرْتُم بَعْدَ إِيمَٰنِكُمْ ۚ إِن نَّعْفُ عَن طَآئِفَةٍۢ مِّنكُمْ نُعَذِّبْ طَآئِفَةًۢ بِأَنَّهُمْ كَانُوا۟ مُجْرِمِينَ ﴿٦٦﴾
And if you ask them, they will surely say, "We were only conversing and playing." Say, "Is it Allah and His verses and His Messenger that you were mocking?" Make no excuse; you have disbelieved after your belief. If We pardon one faction of you - We will punish another faction because they were criminals.
Mocking the religion is disbelief even when called a joke.
Quran, Surah An-Nisaa 4:140
وَقَدْ نَزَّلَ عَلَيْكُمْ فِى ٱلْكِتَٰبِ أَنْ إِذَا سَمِعْتُمْ ءَايَٰتِ ٱللَّهِ يُكْفَرُ بِهَا وَيُسْتَهْزَأُ بِهَا فَلَا تَقْعُدُوا۟ مَعَهُمْ حَتَّىٰ يَخُوضُوا۟ فِى حَدِيثٍ غَيْرِهِۦٓ ۚ إِنَّكُمْ إِذًۭا مِّثْلُهُمْ ۗ إِنَّ ٱللَّهَ جَامِعُ ٱلْمُنَٰفِقِينَ وَٱلْكَٰفِرِينَ فِى جَهَنَّمَ جَمِيعًا ﴿١٤٠﴾
And it has already come down to you in the Book that when you hear the verses of Allah [recited], they are denied [by them] and ridiculed; so do not sit with them until they enter into another conversation. Indeed, you would then be like them. Indeed Allah will gather the hypocrites and disbelievers in Hell all together -
Believers should leave gatherings where the religion is mocked.
Sahih al-Bukhari 6478
Sahih... إن العبد ليتكلم بالكلمة من سخط الله لا يلقي لها بالا يهوي بها في جهنم ...
"A servant may say a word that angers Allah without giving it a thought, and fall by it into Hell."
Careless words about the religion can destroy a person.
Where the ruling is recorded
- al-Fatawa al-Hindiyya, Kitab al-Siyar, chapter on the rulings of apostates. Lists words of mockery that take a person out of Islam, and advises renewing faith and nikah.
- Radd al-Muhtar (Ibn Abidin), Bab al-Murtadd. Mockery of the religion is kufr even in jest; caution in judging individuals.
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.