Ruling on insulting any Prophet, Companion or Angel
3-9-2016 | IslamWeb
Question:
Assalaamu alaykum. 1. I have heard that if a person insults the Prophet, sallallaahu 'alayhi wa sallam, he becomes a disbeliever. Will a person become a disbeliever if he insults other Prophets? 2. Will a person become a disbeliever if he insults the Companions or the angels.
Answer:
All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad 
is His slave and Messenger.
The ruling on insulting the Prophets or Angels is like the ruling on insulting the Prophet ; that it is major Kufr (disbelief) that takes a person out of the fold of Islam.
The Kuwaiti Fiqh Encyclopedia reads:
“The scholars of Fiqh agreed that insulting the Prophets of Allaah or His Angels – who are mentioned in the Quran and authentic Sunnah – or disparaging them or accusing them of lying regarding what they came with, or denying their existence and denying that they were sent (by Allaah); the one who does so is killed for his Kufr (disbelief). Al-Mawwaaq said, 'All this is in regard to the ones who are confirmed to be among the Prophets or the Angels like Jibreel (Gabriel). As for those who were not specifically proven by Islamic texts to be among the Angels or the Prophets, such as Haaroot and Maaroot, Luqmaan, Thul-Qarnayn, Maryam and their like, then the ruling about the person who belittles them is not as we mentioned because that inviolability (of the Prophets and Angels) is not proven for them, but such a person who belittles them should be disciplined.'” For more benefit, please refer to fatwa 53874.
As for insulting the Companions, it is not Kufr in all cases; rather, there are some details about it.
The Kuwaiti Fiqh Encyclopedia reads:
“Whoever insults the Companions, or insults one of them, then if he attributes to them something that does not slander their trustworthiness or their religion, such as describing some of them to be stingy or to lack courage, knowledge, or asceticism, and so on, then such a person does not go out of the fold of Islam, according to the agreement of the scholars, but he deserves to be disciplined.
However, if he accused them of something that undermines their religion or their trustworthiness, such as accusing them of adultery, then the scholars agreed that a person who accuses ‘Aa’ishah 
(the wife of the Prophet ) of adultery, which is something which Allaah declared her innocent of, then such a person goes out of the fold of Islam, because he is denying the text of the Quran.
With regard to the rest of the Companions, the scholars differed in opinion about the one who slanders them. The majority of the scholars said: A person does not go out of the fold of Islam due to insulting one of the Companions, even ‘Aa’ishah in other than what Allaah declared her innocent of.
Also, a person goes out of the fold of Islam if he declares that all the Companions are disbelievers or says that the Companions renounced Islam after the death of the Prophet or says that they had become dissolute; because this is a denial of what is explicitly said in the Quran in many contexts regarding the fact that Allaah is pleased with them and His praise of them. Making such a statement implies that those who transmitted the Quran and Sunnah to us are disbelievers or dissolute or that this nation, which is the best nation on earth, and the best of which are the first generation, that most of them were disbelievers or dissolute, which in turn implies that this nation is the most evil one among other nations and that its predecessors [the first generation] are the most evil people. That the person who says such a thing is a disbeliever is something that is known in religion by absolute evidence.”
Allaah knows best.