Iblīs (Arabic إبليس), is the primary devil in Islam.
He appears more often in the Qur'an (Islamic holy Book) as the Shaitan, a term used to refer to all of the evil spirits assisting Iblis, but which is often used to refer to just Iblis. Iblis is mentioned 11 times, and Shaitan "al-Shaitaan" (الشيطان) 87 times. He is chief of the spirits of evil (Shaitan), and his personality is similar to that of the devil in Christianity.
Iblis was a Jinn, a creature made of smokeless fire by God (like humans are made of 'clay'). In an outburst rooted in envy, Iblis disobeyed Allah and was expelled from the grace of Allah. He was later sent to earth along with Adam and Eve after having lured them into eating fruit from the forbidden tree, although in this role he is always referred to as ash-Shaitan. He was condemned consequently by God to Hell. He replied with saying that he wanted to bring the inhabitants of Earth down with him, and God, to test Mankind and Jinn, allowed him to roam Earth to attempt to misguide others.
He tempts humans through his whisper (waswas, "he whispered") of sinful ideas in their head and false suggestion (haiif). In the end, it is believed, he will be cast into Jahannam (Hell in Islam) along with those who give in to his temptation of sinful ideas and disobeyed God's true message to mankind (Islam), while those who successfully try to follow a righteous path will be rewarded with the pleasures of Jannah (Paradise or Heaven in Islam).
The Qur'an does not depict Shaitan as the enemy of Allah, for Allah is supreme over all his creations and Iblis is just one of his creations. Unlike the Zoroastrian beliefs, all good and bad deeds are from Allah himself and only he can save humanity from the evils of his universe and his creations. Shaitan's single enemy is humanity. He intends to discourage humans from obeying God. Thus, humankind is warned to struggle against the mischiefs of the Shaitan and temptations he puts them in. A commonly shared belief in both Islam and Christianity is that the universal existence of evil in personal lives is usually experienced because of the devil.
Non-Muslim scholars generally hold Iblis to be a contraction of the Greek word diabolos, meaning "devil". They claim that the Christian and Jewish communities of Arabia during Muhammad's time are likely to have known the word from Greek translations of the Hebrew Bible and the Gospels. Muslim scholars, on the other hand, are more inclined to derive the word from the Arabic verbal root balasa بلس, meaning "he despaired".
According to the Qur'an, after God had completed the creation of everything else (2-29), God announced that He will create a Khalifa (viceregent) on Earth, causing the angels to exclaim how He intends to place on earth one who shall make mischief and shed blood (mankind) while they hymn His praise and sanctify Him. It caused them to receive the answer that He knows what they do not (2-30).
So God created Adam and gave him from His knowledge what no other creature of his possess, by teaching him the names of everything, and by presenting them to the angels, God demanded that they tell the names (2-30), knowing that they will fail.
After the angels have admitted that they have no knowledge except that which God (Arabic: Allah) had given them (2-30), God commanded Adam to display his knowledge in front of the angels (2-33), and when Adam did, He commanded the angels to prostrate before Adam, so they do except for Iblis (2-34), (7-11), (20-116).
In another version of the story God informs the angels that He will create Man (Bashar) from clay (15-28) and that as soon as He has completed his creation they should all prostrate before His creation (15-29), and so they all do (15-30), except for Iblis (15-31), (38-74) When Allah demanded an explanation from Iblis of why he refused to prostrate to Adam (15-32), and Iblis explains that he would not prostrate before Adam whom Allah has created from clay (15-33) (17-61), while he himself Iblis was created from fire (38-76), and as such he was better than Adam (7-12).