Fundamentals of Islam
1)Usool -ad-Deen (Roots of Religion)
a) Tawheed - (Oneness of God) - The most fundamental aspect of all beliefs revolves around the total acceptance of the Absolute and Perfect Creator. Belief in the Originator of all causes and effects with no effect on Him and that He is One, Everliving, Beneficent and Merciful. He has neither a colleague nor a partner. He begets not, nor is He begotten, and there is none like Him. The Almighty God is Unique and is Absolute in the Absolute sense. No entity in His Universe can ever comprehend His true state and none should even bother to try for it will lead to futility and insanity. Yet there is no doubt in any sane mind that His existence precedes all and His presence is Absolutely ubiquitous (everpresent). For anyone to say that God does not exist is a gravely mistakn because such a person can NEVER disprove His existence, whether scientifically or philosophically, or for that matter in any method known. Because He is Absolute and none is like Him, no one in the relative world can ever physically define Him, and thus all idol worshippers and those who ascribe a shape or a body to Him are wrong. Ascribing a shape to the One who is beyond our limited perceptions would be tantamount to lying and giving a false appearance and a false representation. In addition, to believe that one can see God in the physical sense of sitting on a throne like some mythical being is certainly an untrue statement and should never be accepted. The Almighty Creator brings to existence everything with utmost Perfection and nothing in His Universe is imperfect. Thus to state that the Creator has created imperfect things is certainly a false statement. He is the One and Only and is Absolutely independent of anything and everything that exists. Glorified be His names, the Most High!
b) 'Adl - (Justice) - Essentially part of Tawheed. Belief that God is Just. He will reward or punish any person according to his deeds and thus the notion of predestination (where all decisions are God's and not any one else's) in one's deeds does not exist. It is absolutely forbidden in Islam to believe that the Almighty, Merciful Allah planned our destiny and that the good and the bad are just His Will and there is no choice for us between them (God forbid!). Those who ascribe to such lies do so because they want to blame their own evils on Allah and claim the good for themselves! Although the attribute of Allah's Justice is not a separate entity of Allah for certainly the Almighty God can never be compartmentalized nor defined in any relative terms, it is nonetheless absolutely compulsory to believe and fully understand the importance of this attribute in Islam so as not to allow the evil suggestions of Iblees (curse of Allah be upon him and his progeny) and his companions from leading us astray.
c) Nubuwwat - (Prophethood) - Belief in the Prophets (PBUT) of God who excel all other persons for whom they are sent for. All prophets of Allah are perfect and sinless (ma'soom). Prophet Muhammad Mustafa (PBUH&HF) is the last of the prophets sent by God and the sealer of prophets for NO more are to come, EVER! The total number of prophets (PBUT) that were sent by God to mankind is 124,000 and every nation on earth was given guidance through them. In fact, all major religions today on earth can be traced to have these divinely guided teachers as their original propagators of the Truth of Allah. The best of His messengers all came from the same tree i.e. family lineage and many of them are mentioned in the Holy Qur'an which describes who they were and what their mission on earth was. It is important to note that no prophet on earth ever negated or rejected any of the other divinely ordained prophets and thus their message was always the same and one in purpose. Each established the law of the One and Only God and showed the way of life for humans to observe. From the very first creation of mankind, there was always a prophet on earth which was Prophet Adam (PBUH). This guidance from the Merciful Allah to establish His complete laws continued to the last Prophet Muhammad (PBUH&HF) who exemplified the letters of the law in his most perfect behavior. He completed and perfected the one and only True religion, Islam. With the revelation of the last Holy Book, the Qur'an, which is the most protected and perfect book of God with us, he established as part of his mission, every concievable and practical law for mankind to follow in order to attain spiritual perfection. Great prophets such as Nuh (Noah), Ibrahim (Abraham), Ismail (Ishmael), Ishaaq (Isaac), Yaqoob (Jacob), Yusuf (Joseph), Dawood (David), Sulaiman (Solomon), Musa (Moses), Yahya (John), and Isa (Jesus), - (Peace be upon them all) - all came from the one blessed lineage of Prophet Adam (PBUH) and ended with the last Messenger, Muhammad (PBUH&HF). It is also important to note that anyone who ascribes imperfections or mistakes to these divinely guided personalities is ascribing it directly to Allah who is certainly free from such. Acceptance of such ideas is also rejection of the message of Allah entirely. Thus with prophethood, a believer has to accept in their complete message without any reservations of possible errors or mistakes.
d) Imamat - (Guidance) - Belief in the divinely appointed leadership after the death of the Holy Prophet (PBUH&HF) to protect and guide mankind with the revealed Truth, the Holy Qur'an and the true practices of the Holy Prophet himself. The roles of these leaders is an integral part in the protection of all the Messengers and their divine Messages. The Almighty Allah appointed through the Holy Prophet himself, twelve Guides (Imams) to protect mankind from misrepresenting and misinterpreting the Truth. Belief in this is most important in Islam and no doubts about their positions should be allowed. They are indeed sinless (ma'soom) and perfect in the highest sense of the word. The Imams have direct knowledge from God, and their verdict is the verdict of God. After the Holy Prophet, only they can interpret and guide mankind in every aspect of life and death and all believers must acquire guidance from them or else they will certainly be lost. They do NOT bring any new laws nor do they ever innovate their own laws. They always exempliy and elucidate the practical (Sunnah) and the written (the Holy Qur'an). It is also important to note that they NEVER disagree with each other in their manners and duties nor in their representations of the Divine Laws. They are from the best and the most blessed and purified lineage of the last Holy Prophet Muhammad (PBUT) and their names are as follows: (1) Imam Ali ibn Abu Talib, the cousin and son-in-law of the Holy Prophet who called him his only brother in this world and in the next, (2) Imam Hasan son of Ali, (3) Imam Husain son of Ali, (4) Imam Ali son of Husain, (5) Imam Muhammad son of Ali, (6) Imam Ja'far son of Muhammad, (7) Imam Musa son of Ja'far, (8) Imam Ali son of Musa, (9) Imam Muhammad son of Ali, (10) Imam Ali son of Muhammad, (11) Imam Hasan son of Ali, and the last and living Imam Muhammad son of Hasan, the establisher of the Truth till the end of this world (PBUT). There is no successor to the Twelfth Holy Imam Muhammad ibnul Hassan (PBUH) and he is LIVING today but is in occultation and appears only to those who are most in need and to those who are most virtuous and pious. By the Command of Allah, he will reappear to all when he will establish true justice on earth and will rule mankind compassionately with utmost perfection as is the Will of the Almighty Allah. He will abolish the evil establishments on earth and mankind will live under true guidance as should have been many centuries ago!
5) Qiyaamat - (Resurrection) - Belief in the Day of Judgement when all human beings shall be raised from the dead and all their good and bad deeds shall be ultimately judged and recompensed accordingly. This belief is most essential WITH the belief in the One True God. The Day of Judgement will prove to all in this Universe that the Almighty Allah is the Creator of all from nothing and is the Absolute Master. His divine presence shall be most apparent on this important Day for all to witness. It is a judgement Dayfor His creatures to know themselves and their relationship to the Creator Allah. Just as pursuit for justice is inseperable in any society on earth, so is the Ultimate Day of Justice inseparable for mankind.
Furoo-ad-Deen (Branches of Religion)
Zakat (Poor Rate)
Khums (Wealth Tax)
Amr-Bil-Ma'roof (Enjoin what is good)
Nahi-Anil-Munkar (Forbid what is wrong)
Tawalla (To love and respect the Ahl-ul-Bait and their friends)
Tabarra (To disassociate from the enemies of the Ahl-ul-Bait)
Taken from "Islam : the living religioun " web site.