the only way to guidance is that of revelation

Man, like the rest of creation, naturally seeks his own well-being and happiness as he lives out his life. Since, by his very make-up, he has a variety of natural needs, he has no alternative but to live in society in order to fulfill these needs; his own well-being and search for the fulfillment of his natural character takes place in the wider framework of society's well-being.
Thus the only acceptable pattern of existence, regulated by a comprehensive law common to all people, is the one which guarantees both the well-being of society and of the individual in a balanced and just fashion. It is also clear that man, like the rest of creation, must endeavour to achieve his well-being and undertake whatever preparation is necessary for achieving this by allowing himself to be guided by his creator.
It is but a logical next step in our analysis to say that any guidance from the Creator must be towards this comprehensive law, common to all and, at the same time, in accord with the individual's well-being. Intellect is not enough to guide man to the law since it does not always decide in favour of cooperation with others nor in favour of the common good.
The path, the way, which fits perfectly the requirements of man is the way taught by the Prophets and messengers of God. It is the way brought to them by God through revelation and established as undeniably true and valid, by the example of their own lives and their intimate knowledge and contact with god.

in chapter ii:213, god says, "Mankind was one community and God sent (to them) prophets as bearers of good news and as warners and revealed to them the book with the truth that it may judge between mankind concerning that in which they differed." Here we under- stand "one community" to mean a society at peace, its members living without dispute or difference. After a period of time, men differed with one another and as a result God sent the prophets.
again he says in iv:163-165, "Indeed We have inspired you as we have inspired Noah ... Messengers of good news and a warning in order that mankind might have no argument against god after the messenger. " Intellect alone does not make man accountable to God and this is why he must be awakened to the reality of his inner condition by other means.
The first of the above-mentioned verses recognizes the way of revelation and prophecy as the only way of removing differences between men. The second shows revelation and prophecy to be the complete and absolute proof to mankind of the truth of god's message.