Answer

Praise be to Allaah. 

Ibless – may Allaah curse him – is one of the jinn. He was not an angel for a single day, not even for an instant. The angels were created noble; they never disobey Allaah when He commands them to do something and they do what they are commanded. This is clearly stated in the Qur’aanic texts which indicate that Iblees is one of the jinn and not one of the angels. These texts include the following:

 1.                     Allaah says (interpretation of the meaning):

“And (remember) when We said to the angels: “Prostrate yourselves unto Adam.” So they prostrated themselves except Iblees (Satan). He was one of the jinn; he disobeyed the Command of his Lord. Will you then take him (Iblees) and his offspring as protectors and helpers rather than Me while they are enemies to you? What an evil is the exchange for the Zaalimoon (polytheists, and wrongdoers, etc).” [al-Kahf 18:50]

 2.                     Allaah stated that He created the jinn from fire, as He says (interpretation of the meaning):

“And the jinn, We created aforetime from the smokeless flame of fire” [al-Hijr 15:27]

“And the jinn He created from a smokeless flame of fire” [al-Rahmaan 55:15]

And it was narrated in a saheeh hadeeth that ‘Aa’ishah said: the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “The angels were created from light, the jinn were created from smokeless fire and Adam was created from that which has been described to you.” (Narrated by Muslim in his Saheeh, no. 2996; also narrated by Ahmad, no. 24668; by al-Bayhaqi in al-Sunan al-Kubra, no. 18207 and by Ibn Hibbaan, no. 6155).

One of the attributes of the angels is that they were created from light, and the jinn were created from fire. It was mentioned in the Qur’aan that Iblees – may Allaah curse him – was created from fire. This is what Iblees himself said when Allaah, may He be glorified and exalted, asked him the reason for his refusal to prostrate to Adam when Allaah commanded him to do so. He – may Allaah curse him – said:

“ ‘I am better than him (Adam), You created me from fire, and him You created from clay’” [al-A’raaf 7:12; Saad 38:76 – interpretation of the meaning]. This indicates that he was one of the jinn.

 3.                     Allaah has described the angels in His Book, where He says (interpretation of the meaning):

“O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allâh, but do that which they are commanded” [al-Tahreem 66:6]

“And they say: ‘The Most Gracious (Allaah) has begotten a son (or children).’ Glory to Him! They [whom they call children of Allaah i.e. the angels, ‘Eesaa (Jesus) son of Maryam (Mary), ‘Uzair (Ezra)], are but honoured slaves. They speak not until He has spoken, and they act on His Command” [al-Anbiyaa’ 21:26-27]

“And to Allaah prostrate all that is in the heavens and all that is in the earth, of the moving (living) creatures and the angels, and they are not proud [i.e. they worship their Lord (Allâh) with humility]. They fear their Lord above them, and they do what they are commanded” [al-Nahl 16:49-50]

So it is not possbile for the angels to disobey their Lord, because they are protected from sin and they are naturally inclined to obey Allaah.

4.                     The fact that Iblees is not one of the angels means that he is not compelled to obey Allaah. He has freedom of will just as we humans do. Allaah says (interpretation of the meaning);

 “Verily, We showed him the way, whether he be grateful or ungrateful” [al-Insaan 76:3]

  There are also Muslims and kaafirs among the jinn. It says in Soorat al-Jinn (interpretation of the meaning):

 “Say (O Muhammad): ‘It has been revealed to me that a group (from three to ten in number) of jinn listened (to this Qur’aan). They said: ‘Verily, we have heard a wonderful Recitation (this Qur’aan)! It guides to the Right Path, and we have believed therein, and we shall never join (in worship) anything with our Lord (Allaah).’” [al-Jinn 72;1-2]

 In the same soorah, it states that the jinn said:

 “‘And indeed when we heard the Guidance (this Qur’aan), we believed therein (Islamic Monotheism), and whosoever believes in his Lord shall have no fear, either of a decrease in the reward of his good deeds or an increase in the punishment for his sins.  And of us some are Muslims (who have submitted to Allaah, after listening to this Qur’aan), and of us some are Al‑Qaasitoon (disbelievers those who have deviated from the Right Path)’…” [al-Jinn 72:13-14]

Ibn Katheer (may Allaah have mercy on him) said in his Tafseer:

 Al-Hasan al-Basri said: Iblees was not one of the angels, not even for a single moment. He is the father of the jinn, just as Adam (peace be upon him) is the father of mankind. This was narrated by al-Tabari with a saheeh isnaad (part 3/89).

Some of the scholars said that Iblees was one of the angels, that he was the peacock of the angels, that he was the one among the angels who strove the hardest in worship… and other reports, most of which come from the Israa’eeliyyaat (stories and reports from Jewish sources), and some of which contradict the clear texts of the Qur’aan.

Ibn Katheer said, explaining this:

A lot of these reports were transmitted from the Salaf, and most of them come from the Israa’eeliyyaat, which may be been transmitted in order to be examined [i.e., as opposed to being accepted as is]. Allaah knows best about the veracity or otherwise of many of them. Some of them are definitely to be rejected, because they go against the truth which we hold in our hands. In the Qur’aan we have sufficient so that we have no need of previous reports, because hardly any of them are free of distortions, with things added or taken away. Many things have been fabricated in them, for they did not have people who had memorized things precisely by heart (huffaaz) who could eliminate the distortions created by extremists and fabricators, unlike this ummah which has its imaams, scholars, masters, pious and righteous people, brilliant critics and men of excellent memory who recorded the hadeeths and classified them, stating whether they were saheeh (sound), hasan (good), da’eef (weak), mawdoo’ (fabricated), matrook (to be ignored). They identified the fabricators and liars, and those about whom nothing was known, and other kinds of men (i.e., narrators). All of this afforded protection to the Prophet (peace and blessings of Allaah be upon him), the Seal of the Messengers and the Leader of Mankind, so that nothing would be attributed to him falsely and nothing would be transmitted from him that he did not say or do. May Allaah be pleased with them and make them pleased [by rewarding them], and make the Paradise of al-Firdaws their eternal abode. (Tafseer al-Qur’aan il-‘Azeem, 3/90).

And Allaah knows best.