It’s a sin and a depravity according to the Qur’an for a believer to criticize a person’s’ defects with mockery. Mockery is a characteristic of those who live in distance from religious moral values and do not fear Allah as should be. These people resort to such methods as caricature etc. When they want to criticize a person or an event and thus exceed the limits of respect and courtesy by choosing a language, which is not compatible with the Qur’anic moral values.
Whereas, a Muslim uses a method of communication while criticizing a manner which he finds not compatible with the Qur’anic moral values and the Hadith, thus he expresses the falsity of the manner in question according to the Qur’an and the Hadith of our Prophet (may Allah bless him and grant him peace). Especially about the issues concerning religion and holy values, he uses careful and mindful tongue as a necessity of his deep love and respect for Allah. Allah mentions in the Qur’an that ordering good and forbidding evil is an important sign of believers:
Those who repent, those who worship, those who praise, those who fast, those who bow, those who prostrate, those who command the right, those who forbid the wrong, those who preserve the limits of Allah: give good news to the believers. (Surat at-Tawba, 112)
Throughout the history, prophets and sincere believers were mocked, and Allah imposed punishments on those who were in depravity against believers:
Messengers before you were also mocked, but those who jeered were engulfed by what they mocked. ( Surat al-An‘am, 10)
Allah mentioned in the Qur’an that mockery is an indecent morality and a sin and thus, believers should avoid such depravity. Moreover, Allah informs believers in a verse in case they encounter an atmosphere where there’s mockery about the religious issues, they should leave or they would be in the position of those who do it:
It has been sent down to you in the Book that when you hear Allah’s Signs being rejected and mocked at by people, you must not sit with them till they start talking of other things. If you do you are just the same as them. Allah will gather all the hypocrites and unbelievers into Hell. (Surat an-Nisa’, 140)
Allah informs us the position of those who resort to mockery in some other verses in the Qur’an.
You who believe! Do not take as friends any of those given the Book before you or the unbelievers who make a mockery and a game out of your believe. Fear [and respect] Allah if you are believers. (Surat al-Ma’ida, 57)
... lest anyone should say, ‘Alas for me for neglecting what Allah was due, and being one of the scoffers!’ (Surat az-Zumar, 56)
When he does learn something of Our Signs, he makes a mockery of them. Such people will have a humiliating punishment. (Surat al-Jathiyya, 9)