Our Holy Prophet Muhammad (peace be upon him and his household) said:
"Whoever makes unlawful deeds lawful, never believed in the Qur'an."1
The Holy Qur'an is Allah's message revealed to Prophet Muhammad (peace be upon him and his household) through His angel Gabriel (A.S.). Allah, the Almighty, ordered the Prophet (peace be upon him and his household) to convey it to all people, to guide them towards peace and goodness, to instruct them in useful actions and to teach them to abstain from evil actions and corruption.
Thus, the Qur'an teaches us issues and matters related to our religion. Among them are: To believe in Allah, His angels, His prophets and the Day of Judgement. To develop good manners and behaviour like telling the truth, love, cooperation, respect of parents, etc. To show us what is lawful (permitted) and what is unlawful (forbidden), urging us towards lawful deeds and forbidding us from unlawful ones. For instance, Allah made the following deeds unlawful (forbidden): robbery, suicide, gambling, lying, injustice, theft, wronging our neighbours, helping oppressors and those guilty of wrongdoing, eating dead animals or the flesh of swine (pork), and drinking alcohol.
It is obligatory for us, as Muslims, to give up these forbidden deeds and others that the Holy Qur'an specifies as forbidden haram. This is so because we believe that everything which is forbidden is useless and fruitless for us and for other people.
Therefore it does not please us to be beaten or have our property stolen or to be deceived or oppressed. We abstain from such forbidden deeds. We realize that every forbidden act is useless to us and if we indulge in them we will suffer Allah's displeasure. It becomes obligatory for us to give them up.
Indeed, whoever gives up deeds forbidden by the Holy Qur'an is a truthful believer of the Qur'an as Allah's word and he always follows it during his life. Whoever does not give up these forbidden actions and does them as if they are lawful is one who does not believe that the Qur'an is Allah's word revealed to His Prophet ... because he does not give up what Allah, the Most High, has forbidden. Hence, we should think, whether a certain act is lawful or unlawful, before saying or doing anything. If it is lawful we may do it, but if it is unlawful we must abstain from doing it. Our Prophet Muhammad (peace be upon him and his household) says: Man is never a true believer unless he gives up deeds forbidden by the Qur'an.
Most Surely it is an Honoured Qur'an, in a Preserved Book.
* A Muslim in Society. Published by: Al Balagh Foundation. P.O. Box 1977/19395, Tehran. Islamic Republic of Iran.
1- Al-Harrani, Tuhaf al-Uqool an aali al-Rasool, p. 39