The so-called "Nation of Islam"
The followers of the Nation of Islam believe in (all quotes taken from their homepage or their publications):
...one God (Allah) and that Allah (God) appeared in the Person of Master W. Fard Muhammad, July, 1930; the long awaited 'Messiah' of the Christians and the 'Mahdi' of the Muslims...
However, the Qur'ân states in chapter 4, verse 36, "Serve Allah, and join not Any partners with Him; ... "
. And according to a Hadith narrated by Masruq, in Sahih Bukhari, 'Ayesha said, "If anyone tells you that Muhammad has seen his Lord, he is a liar, for Allaah says (in 6:103), 'No vision can grasp Him.'...".
The followers of the Nation Of Islam further believe "in the resurrection of the dead--not in physical resurrection--but in mental resurrection. We also believe that the so-called Negroes are most in need of mental resurrection; therefore, they will be resurrected first."
But the Qur`an states in chapter 20, verse 55, "From the earth did We Create you, and into it Shall We return you, and from it shall We bring you out once again."
Even more pointedly, the Qur'an also states in 64:7,
The Unbelievers think that they will not be raised up (for Judgement). Say: "Yea, by my Lord, Ye shall surely be Raised up: then shall ye Be told (the truth) of All that ye did. And that is easy for Allah."
Besides the above two differences, the followers of the Nation of Islam also believe in other things contrary to Islam as defined in the Qur'an and Sunnah, such as:
[We, the Black Muslims, believe] "in the truth of the Bible, but we believe that it has been tampered with and must be reinterpreted so that mankind will not be snared by the falsehoods that have been added to it".
The problem with this belief: The true Prophet of Islam ordered Muslims to neither accept the Bible nor reject it - certainly there was no mention of reinterpretation.
"That we who declare ourselves to be righteous Muslims, should not participate in wars which take the lives of humans. We do not believe this nation should force us to take part in such wars, for we have nothing to gain from it unless America agrees to give us the necessary territory wherein we may have something to fight for".
The problem with this belief: The Qur'an and Sunnah are crystal clear on the necessity of going to war when the situation demands it.
The Nation of Gods and Earths (5% Nation of Islam)
The Nation of Gods and Earths (5% Nation of Islam) is apparently an offshoot of the so-called Nation of Islam. Like its parent, this group's beliefs clearly identify it as being fundamentally outside the pale of Islam. Specifically, and we quote (from their homepage):
The original man is the Asiatic Blackman, the maker, the owner, the cream of the planet Earth, father of civilization, God of the Universe.
...the blackman is god and his proper name is ALLAH. Arm, Leg, Leg, Arm, Head.
This is in clear contradiction with one of the essential axioms of Islam, namely that Allah (God) is Creator and all else (including men - asiatic blacks or otherwise) is created. In chapter 25, verse 54 of the Qur'an, Allah says that He has created man, therefore it is logically impossible for man to be Allah.
The second quote above is a prime example of a tendency of the "Nation of Gods and Earths" to conjure up beliefs that are, to a large extent, highly confused. Some examples of these beliefs that have nothing to do with Islam are "supreme mathematics and alphabet", an evil person named Yacob, a prophet named W. D. Fard, and a belief that black people are superior in some way.
The true Prophet of Islam, Muhammad pbuh, refuted this last racist belief in his Farewell Address,
O people! Verily your Lord is one and your father is one. All of you belong to one ancestry of Adam and Adam was created out of clay. There is no superiority for an Arab over a non-Arab and for a non-Arab over an Arab; nor for white over the black nor for the black over the white except in piety. Verily the noblest among you is he who is the most pious.
For a deeper expose of this group and its parent (the Nation of Islam), the interested reader might wish to examine the autobiography of the late Malik Al-Shabazz (Malcolm X).