One of the greatest reasons for which Allah has created us – which is one of the greatest tests – is the command to affirm His Oneness (Tawhid) and to worship Him Alone with no partner or associate. For more, see the detailed answer.

1- With regard to numbers, there is one Hell and one Paradise, but each of them has degrees and levels. The levels of Hell differ according to the extent of their inhabitants’ disbelief in this world. The hypocrites will be in the lowest level of Hell. We know of no limit to the number of degrees and levels in Paradise. It was said that their number is equal to the number of verses in the Quran. 2- The Sunnah describes the position of those who do certain actions. For example: 1- Faith in Allah and in the Messengers, 2-Jihad, 3-Those who sincerely desire martyrdom, 4- giving out in charity, 5- Doing wudu properly, and 6- Memorizing Quran