The Qur'an Contains a Pattern of a Complete Way of Life for Man. The religion of Islam is superior to any other in that it guarantees happiness in man's life. For Muslims, Islam is a belief system with moral and practical laws that have their source in the Qur'an. God, may He be exalted, says:
"Indeed this Qur'an guides to the path which is clearer and straighter than any other". (XVII:9)
He also says:
"We have revealed to you the book which clarifies every matter". (XVI :89)
These references exemplify the numerous Qur'anic verses (ayat) which mention the principles of religious belief, moral virtues and a general legal system governing all aspects of human behavior. A consideration of the following topics will enable one to understand that the Qur'an provides a comprehensive programme of activity for man's life. Man has no other aim in life but the pursuit of happiness and pleasure, which manifests itself in much the same way as love of ease or wealth.
Although some individuals seem to reject this happiness, for example, by ending their lives in suicide, or by turning away from a life of leisure, they too, in their own way, confirm this principle of happiness; for, in seeking an end to their life or of material pleasure, they are still asserting their own personal choice of what happiness means to them. Human actions, therefore, are directed largely by the prospects of happiness and prosperity offered by a certain idea, whether that idea be true or false. Man's activity in life is guided by a specific plan or programme. This fact is self-evident, even though it is sometimes concealed by its very apparentness.
Man acts according to his will and desires; he also weighs the necessity of a task before undertaking it. In this he is promoted by an inherent scientific law, which is to say that he performs a task for "himself" in fulfilling needs which he perceives are necessary. There is, therefore, a direct link between the objective of a task and its execution. Any action undertaken by man, whether it be eating, sleeping or walking, occupies its own specific place and demands In the usage of the Qur'an, the word din (1) is basically applied to a way, a pattern of living, and neither the believer nor the non-believer is without a path, be it prophetic or man-made. God, may He be exalted, describes the enemies of the divine din (religion) as those:
"Who prevent others from the path of God and would have it crooked". (VII:45)
This verse shows that the term Sabil Allah - the path of God - used in the verse refers to the din of fitra - the inherent pattern of life intended by God for man). It also indicates that even those who do not believe in God implement His din, albeit in a deviated form; this deviation, which becomes their din, is also encompassed in God's programme. The best and firmest path in life for man is the one which is dictated by his innate being and not by the sentiments of any individual or society.
A close examination of any part of creation reveals that, from its very inception, it is guided by an innate purpose towards fulfilling its nature along the most appropriate and shortest path; every aspect of each part of creation is equipped to do so, acting as a blueprint for defining the nature of its existence.
Indeed all of creation, be it animate or inanimate, is made up in this manner. As an example, we may say that a green-tipped shoot, emerging from a single grain in the earth, is "aware" of its future existence as a plant which will yield an ear of wheat. By means of its inherent characteristics, the shoot acquires various mineral elements for its growth from the soil and changes, day by day, in form and strength until it becomes a fully-matured grain-bearing plant - and so comes to the end of its natural cycle.
Similarly, if we investigate the life-cycle of the walnut tree, we observe that it too is "aware", from the very beginning, of its own specific purpose in life, namely, to grow into a big walnut tree. It reaches this goal by developing according to its own distinct inherent characteristics; it does not, for example, follow the path of the wheat-plant in fulfilling its goal just as the wheat-plant does not follow the life pattern of the walnut tree.
Since every created object which makes up the visible world is subject to this same general law, there is no reason to doubt that man, as a species of creation, is not. Indeed his physical capabilities are the best proof of this rule; like the rest of creation, they allow him to realize his purpose, and ultimate happiness, in life.
Thus, we observe that man, in fact, guides himself to happiness and well-being merely by applying the fundamental laws inherent in his own nature. This law is confirmed by God in the Qur'an, through His Prophet Moses, when he says:
"Our Lord is He who gave everything its nature, then guided it". (XX:50)
It is further explained in IXXXVII: 2-3 as:
"He who created and fashioned in balanced proportion and He who measures and guides".
As to the creation and the nature of man, the Qur'an says:
"By the soul and Him who fashioned it and then inspired it with wrong action and fear of God; he is truly successful who causes it to grow and purifies it and he is a failure who corrupts and destroys it". (XCI:7-l0)
God enjoins upon man the duty to "strive towards a sincere application of the din," (that is, the fitrah of God, or the natural code of behavior upon which He has created mankind), since:
"There is no changing (the laws of) the creation of God". (XXX: 30)
He also says that:
"In truth, the only deen recognized by God is Islam". (III: l9)
Here, Islam means submission, the method of submission to these very laws. The Qur'an further warns that:
"The actions of the man who chooses a din other than Islam will not be accepted". (III: 85)
The gist of the above verses, and other references on the same subject, is that God has guided every creature - be it man, beast or vegetable - to a state of well-being and self-fulfilment appropriate to its individual make-up. Thus the appropriate path for man lies in the adoption of personal and social laws particular to his own fitrah (or innate nature), and in avoiding people who have become "denaturalized" by following their own notions or passions.
It is clearly underlined that fitrah, far from denying man's feelings and passions, accords each its proper due and allows man's conflicting spiritual and material needs to be fulfilled in a harmonious fashion. Thus, we may conclude that the intellect 'Aql should rule man in matters pertaining to individual or personal decisions, rather than his feelings. Similarly, truth and justice should govern society and not the whim of a tyrant or even the will of a majority, if that be contrary to a society's true benefit.
From this we may conclude that only God is empowered to make laws, since the only laws useful to man are those which are made according to his inherent nature. It also follows that man's needs, arising from his outward circumstance and his inner reality, are fulfilled only by obeying God's instructions (or laws). These needs may arise through events beyond man's control or as a result of the natural demands of his body. Both are encompassed in the plan of life that God has designated for man. For, as the Qur'an says, the "decision rests with God only". (XII: 40 and 67)
Which is to say that there is no governance (of man or society, of the inner or the outer) except that of God. Without a specific creational plan, based on the innate disposition of man, life would be fruitless and without meaning. We may understand this only through belief in God and a knowledge of his Unity, as explained in the Qur'an.
From here we may proceed to an understanding of the Day of Judgment, when man is rewarded or punished according to his deeds. Thereafter, we may arrive at a knowledge of the prophets and of prophetic teachings, since man cannot be judged without being first instructed in the matter of obedience and disobedience.
These three fundamental teachings are considered to be the roots of the Islamic way of life. To these we may add the fundamentals of good character and morals which a true believer must possess, and which are a necessary extension of the three basic beliefs mentioned above. The laws governing daily activity not only guarantee man's happiness and moral character but,
more importantly, increase his understanding of these beliefs and of the fundamentals of Islam. It is clear that a thief, a traitor, a squanderer or a libertine do not possess the quality of innocence; nor can a miser, who hoards money, be called a generous person. Similarly, some- one who never prays or remembers God cannot be called a believer in God and the Last Day, nor be described as His servant.
From this we may conclude that good character flourishes when joined to a pattern of correct actions; morals are to be found in the man whose beliefs are in harmony with these fundamentals. A proud man cannot be expected to believe in God nor be humble in respect to the Divine; nor can the man, who has never understood the meaning of humanity, justice, mercy or compassion, believe in the Day of Rising and the Judgment. Chapter XXXV:10 speaks of the relationship between a sincere system of belief and a fitting character:
"Pure speech rises up to Him and He raises up good deeds still further".
And in chapter XXX:10 we learn again of this relationship between belief and action:
"Then evil was the consequence of those who do wrong action because they denied the signs of Allah and they made a mock of them".
To summarize, the Qur'an is composed of the following Islamic fundamentals which together form an interlocking whole: a primary system of belief in the Unity of God, Prophethood and the Day of Reckoning, accompanied by a second group of beliefs, namely, belief in the Tablet, the Pen (which delineates the sequence of cosmic events), the rule of destiny and the decree (without implying pre-determination), the angels, the throne of the Creator, and, finally, in the creation of the sky, the earth and everything between them.
Thereafter, we observe that man's well-being lies in his character being in harmony with these principles. The shariah, namely the laws and code of behavior explained in the Qur'an and commented upon in every detail by the model of the Prophet's life, is the means whereby a man may practise these principles.
At this point we should add that the Prophet's family are his chosen heirs and are entrusted with the task of exemplifying and explaining further the prophetic message and the shariah after the Prophet's death. The Prophet himself has shown that the tradition, hadith, known as the hadith (2) al-thaqalayn which all sects of Islam accept, refers specifically to this matter of succession.
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The Qur'an as a Document of Prophethood
The Qur'an refers on several occasions to the fact that it is the word of God, that it issues from a divine source in the very words in which the Prophet received them and which he later transmitted. The divine nature of the Qur'an is affirmed in several verses.
In III:33-34 we read:
"Or they say that (the Prophet) is inventing it. Indeed they do not believe. If they are truthful then let them produce words like it".
Likewise in XVII:88:
"Say (O Muhammad), if all the jinn and mankind were to join forces to produce something like this Qur'an they could not produce it even if they were to help one another".
Again, in XI:13:
"Or they say he has invented it! Say: then produce ten verses like it which you have invented".
And again in X:38:
"Or they say he has invented it. Say: produce a single chapter like it".
We find further proof. The following challenge is made in Chapter II: 23:
"And if you are in doubt concerning that which we have revealed to Our slave then produce a chapter like it".
Here it should be noted that the Qur'an is addressing those who grew up with Muhammad, the man they knew to be unlettered and untutored in the matters spoken about in the Qur'an. Despite this knowledge, they still doubt. Another challenge is issued, (to those who would find contradictions in the Qur'an, but obviously cannot):
"Will they not reflect upon the Qur'an? If it had been from other than God, they would have found in it much incongruity". (IV: 82)
Since everything in the world is in a state of growth and self-perfection, then the Qur'an would of necessity lack harmony since it was revealed over a period of twenty-three years; it would lack harmony that is if we were to suppose that it was the work of a man rather than of a prophet. The Qur'an, whose messages announce and confirm that it is the work of God, also teaches us that Muhammad is a messenger, sent by God, thus confirming the authenticity of the Prophet. In chapter XIII:43 God speaks Himself, as on many occasions, confirming that He is witness and testimony to the prophecy of Muhammad:
"Say God is sufficient witness between you and me".
The verse refers to disbelievers and defies their disbelief. In another verse, the testimony of angels is added to that of God's:
"But God testifies concerning that which he has resealed to you; He has revealed it in His knowledge; and the Angels also testify. And God is sufficient witness". (IV:166)

Footnotes:
1. Usually translated to mean religion, the word strongly implies transaction between the Debtor (God) and the indebted (man). Hence, living the din means repaying one's debt to the Creator.
2. A report of the words or deeds of the Prophet which has been transmitted to us intact by a chain, or numerous chains, of trustworthy narrators. The tradition in question here possesses an unbroken chain of transmission back to the Prophet himself; these verses confirm the miraculous quality of the book and state that it is beyond the power of man to produce such a work.

Allamah Tabatabaee, The Qur'an In Islam, p. 17-22