Possibility that devils revert to Islam
1-1-2018 | IslamWeb
Question:
Assalaamu alaykum wa rahmatullaahi wa barakaatuhu, Shaykhs. Is it possible that a devil repents and turns to Islam? Human devils do repent and turn to Islam, so what about jinn devils? May Allah reward you, Shaykhs.
Answer:
All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
Scholars held different views regarding the possibility that devils may embrace Islam, except for the Devil (Satan/Iblees) himself. Some scholars held that it is possible that devils embrace Islam. Shaykh ʻUmar Al-Ashqar 
addressed this topic in his book ʻAalam Al-Jinn wa Ash-Shayaateen. He wrote:
"Is it possible that the devil embraces Islam?
The devil, Iblees, can never embrace Islam, because Allah informed us that he will persist in Kufr (disbelief). As for other than him, however, it seems to us that devils can embrace Islam, as evidenced by the fact that the devil companion of the Prophet, sallallahu ‘alayhi wa sallam, embraced Islam. However, some scholars rejected this opinion and held that a devil can never be a believer. Ibn Abi Al-ʻIzz, who wrote a commentary on Al-ʻAqeedah At-Tahaawiyyah, said, 'The devil companion of the Prophet, sallallahu ‘alayhi wa sallam, did not revert to Islam; rather, he submitted to him and obeyed him.' Some scholars held that the word used in the hadeeth is read 'Fa-aslamu' meaning 'so I am safe from his evils' (as opposed to 'Fa-aslama' meaning 'so he reverted to Islam').' Although Ibn Abi Al-ʻIzz held that this version (Fa-aslamu) involves distorting the hadeeth, An-Nawawi said in his commentary on Saheeh Muslim, 'These are two famous versions of the hadeeth.' He said that Al-Khattaabi held the version reading 'Fa-aslamu' (so I am safe from his evil) as preponderant. It was narrated that Al-Qaadhi ʻIyaadh chose the version reading 'Fa-aslama' (he reverted to Islam), and that is also the opinion chosen by An-Nawawi.
Among those who held that the devil may embrace Islam was Ibn Hibbaan. He commented on the hadeeth, saying: 'It is deduced that the devil companion of the Prophet, sallallahu ‘alayhi wa sallam, reverted to Islam and used to command him to do what is lawful only; however, it should be noted that had his devil companion been a disbeliever, he, sallallahu ‘alayhi wa sallam, would still have been safe from his evil.'
The opinion of Ibn Abi Al-ʻIzz that the devil can only be a disbeliever is debatable. If he believes that the term devil is used to refer to the disbelieving jinn exclusively, then his opinion would be correct, but if he believes that the devil can never revert to Islam, then that is quite far-fetched, and the hadeeth proves otherwise. It is sufficient to know that Satan was once a believer, but he then disbelieved in his Lord, and that the devils are required to believe in Allah and shall be held accountable for their disbelief. Belief and disbelief are two states that may alternate in this creature, just as they alternate in humans."
The author of Al-ʻUrf Ash-Shathi Sharh Sunan At-Tirmithi said, "I believe that it is possible that the devil would embrace Islam."
Allah knows best.