Reviling any of the Prophets constitutes disbelief and apostasy
Question

If a Muslim reads these publications published by the disbelievers which revile and insult our Prophet (blessings and peace of Allah be upon him), and is angered by that, and in reaction to that – in order to annoy the Christians – he utters inappropriate words about Sayyidina ‘Isa (peace be upon him), what is the ruling on that? How can he repent, and does he have to offer any expiation?
Praise be to Allah.The creed of the Muslim does not only make it obligatory to believe in all the Prophets; rather it also makes it obligatory for him to respect them, honour them, and show great veneration towards them, as is befitting to them, because they are the best of humanity and Allah’s elite among His creation. They are the light of guidance which illuminated the earth after it had been dark and brought comfort to people’s hearts after alienation. There is no way to attain happiness and success except by following their guidance.
Hence all the scholars are unanimously agreed that it is haram to revile or mock the Prophets, and that the one who commits this grievous sin has apostatized from the religion of Islam, just as the one who reviles our Prophet Muhammad (blessings and peace of Allah be upon him) has apostatized from Islam. The Muslim does not differentiate between the Prophets and Messengers of Allah, as He, may He be glorified and exalted, says (interpretation of the meaning):
{Say, “We have believed in Allah and in what was revealed to us and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Descendants, and in what was given to Moses and Jesus and to the prophets from their Lord. We make no distinction between any of them, and we are Muslims [submitting] to Him”} [Al ‘Imran 3:84].
Allah, may He be glorified and exalted, has commanded us to honour and respect our Prophet (blessings and peace of Allah be upon him), and the same ruling applies to all of the Prophets. Allah, may He be glorified and exalted, says (interpretation of the meaning):
{Indeed, We have sent you as a witness and a bringer of good tidings and a warne
That you [people] may believe in Allah and His Messenger and honor him and respect the Prophet and exalt Allah morning and afternoon} [al-Fath 48:8-9].
Here we will quote the words of some scholars, declaring the one who shows disrespect to any of the Prophets to be a disbeliever.
Ibn Nujaym al-Hanafi (may Allah have mercy on him) said:
Criticising any Prophet in any way renders one a disbeliever."(Al-Bahr ar-Ra’iq  5/130).
Al-Qadi ‘Iyad (may Allah have mercy on him) said:
Whoever shows disrespect to him – meaning our Prophet (blessings and peace of Allah be upon him) – or any of the Prophets, or criticises them, or causes harm to them, or kills a Prophet, or fights him, is a disbeliever according to scholarly consensus."(Ash-Shifa bi Ta‘rif Huquq al-Mustafa  2/284).
Ad-Dardir al-Maliki said:
The one who reviles a Prophet on whose prophethood there is scholarly consensus, or says insulting words about a Prophet, has disbelieved."(Hashiyat ad-Dasuqi ‘ala ash-Sharh al-Kabir  4/309).
Ash-Sharbini (may Allah have mercy on him) said:
Whoever disbelieves in a Messenger or Prophet, or reviles him, or shows disrespect to him or his name… has disbelieved."(Mughni al-Muhtaj  5/429).
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
One of the unique characteristics of the Prophets is that whoever reviles any of the Prophets is to be executed, according to the consensus of the ummah, and he is an apostate, just as the one who disbelieves in him and in the message he brought is an apostate. Faith cannot be complete without belief in Allah, His angels, His Books and His Messengers."(As-Safadiyyah 1/262).
Whoever has committed this grave sin must hasten to repent sincerely and to come back to Islam by uttering the twin declaration of faith (shahadatayn) and venerating all of the Prophets. Then he must have complete certainty that we are closer to the Messengers and Prophets than all other nations who attribute themselves to them, and that we must defend all of the Prophets if anyone reviles them or says offensive words concerning them. Defending our Prophet (blessings and peace of Allah be upon him) means respecting all the Prophets, telling all people about their virtues, highlighting the connection between their messages, and telling people that they are as the Prophet (blessings and peace of Allah be upon him) said: “The likeness of me and the Prophets who came before me is that of a man who built a house and built it well and made it beautiful, except for the space of a brick in one of its corners. The people started walking around it, admiring it and saying: ‘Why has this brick not been put in place?’ I am that brick, I am the Seal of the Prophets.” Narrated by al-Bukhari (3535) and Muslim (2287).
And Allah knows best.