quality:correction, structural:summarization
Seven stages of punishment

The seven gates of jahannam, mentioned in the Quran, inspired Muslim exegetes (tafsir) to develop a system of seven stages of hell, analogue to the seven doors of paradise. The stages of hell get their names by seven different terms used for hell throughout the Quran. Each is assigned for a different type of sinners. The concept later accepted by Sunni authorities list the levels of hell as follows, although some stages may vary:

The highest level (jahannam) is traditionally thought of as a type of purgatory reserved for Muslims. Polytheism (shirk) is regarded as a particularly grievous sin; therefore entering Paradise is forbidden to a polytheist (mushrik) because his place is hell; and the second lowest level (jahim) only after the bottomless pit for the hypocrites (hawiyah), who claimed aloud to believe in God and his messenger but in their hearts did not.