The greatest aim of Divine Messengers was to emphasize the importance of refinement, purification, and training of human selves. God-Almighty said in the Holy Quran:
“God did confer a great favor on the believers when he sent among them an apostle from among themselves rehearsing unto them the signs of God, sanctifying them and instructing them in scripture and wisdom, while before that, they had been in manifest error.” -the Holy- Quran (13: 164)
Therefore, it is obvious that the subject of human education and training was of such vital importance that God-Almighty sent Divine Messengers especially for this purpose thus, conferring a great favor ul1on the believers. The individual as well as collective personality, prosperity or cruelty (of this world and Hereafter) of a human being depends upon how much efforts he had already made or is still making for self-building. It is from this consideration that self-building is regarded something of such vital importance because it determines ones eventual destiny.
The Divine Messengers came to teach human beings regarding the path of self-building, nourishment, and perfection of self, as well as to accompany them as their guide and helper in this vital and determinant task.
They came for cleansing and sanctifying human selves from their indecent moral characteristics and animal instincts, and bestowing upon them superior spiritual virtues. The prophets lectured human beings about the self-building program, acted as helper and knowledgeable guides in identifying the ugliness in their moral conducts, and showed them the ways and means for self-control against their selfish whims and passions. By timely issuance of warning and intimidating they succeeded in sanctifying the human selves from the moral obscenities and indecencies. They came for plantation of sapling of higher moral virtues within human souls, nurtured and protected it for its eventual blooming, and in doing so acted as guides, friends, and helpers of the people by encouraging and pursuing them towards the desired sublime' objectives. The Holy Prophet (S) has said:
"I emphasize the importance of good morals for you because God-Almighty has sent me especially for this purpose.” -Bihar al-Anwar vol. 69, p-375.
He further said:
"I was appointed for the Prophethood so that I may accomplish the important task of moral perfection within human souls.” -al-Mustadarak, vol. 2, p-282.
Imam al-Sadiq (A) said:
"God-Almighty appointed prophets with good morals; therefore, whoever discovers these virtues within himself should be thankful to God for this bounty, whoever lacks these virtues must pray, cry, and shed tears 1before God Almighty asking for such blessing." -al Mustadarak, vol. 2, p-283.
The commander of faithful Imam Ali (A) said:
"Supposedly, if neither there was any desire for Paradise nor there was any fear of Hell, and also there would have not been any belief about the reward and punishment in the Next World; even then it would have been be fitting to strive for moral perfection, because, good morals are the path towards prosperity and victory." -al Mustadarak, vol. 2, p-283.
Imam Baqir said:
"The most perfect believers from the point of view of faith are the ones who excel in moral conduct.” -al-Kafi, vol. 2, p-99.
The Holy Prophet (S) said:
“There is nothing better than good moral conduct which could be written on the "Letter of Deeds" on the Day of Resurrection." -al-Kafi, vol. 2, p-99.
And said
“My Ummah will enter into Paradise mostly on the basis of piety and excellence in moral conduct." -al-Kafi, vol. 2, p-l00.
and the following narration:
"A man approached the Holy Prophet (S) and asked: 'What is religion?' The Holy Prophet (S) replied: 'Good moral conduct.' The man asked the same questions from the Holy Prophet (S) alternatively by appearing from right, left, and behind the Messenger. Finally the Holy Prophet (S) took a deep look at him and said: 'Why don't you understand?' Religion is defined as never to get angry." -Mohajateh al-Baiza, vol. 5, p-89.
Islam has attached special importance for moral ethics, and because of these consideration the Holy Quran contains relatively more verses regarding ethics as compared verses related to obligation. Inside the books of narrations, one may finds thousands of narrations regarding ethics as compared to narrations dealing with other topics; if this number is not regarded greater in quantity, certainly it is not smaller either. The rewards and promises mentioned for good moral deeds are certainly not lesser than the rewards prescribed for other actions, and likewise the warnings and punishments described for indecent moral actions are certainly not less than the punishments for other actions.
Therefore, in Islam, ethics constitutes the basics and should not be treated simply as secondary religious obligations or something related to the beautification and decoration of religious persons. If religion has defined do's and don'ts for obligations, it has defined the same for ethics. If encouragement, persuasion, rewards, punishment, and warnings have been utilized for obligations, the same approach has been applied for ethics as well as. Therefore, there exists no difference between ethics and obligations as for as religious recommendations are concerned, and in order to achieve perfection and prosperity one cannot remain ignorant of ethical matters.
The moral obligations cannot be ignored by taking the excuse of treating them simply as moral obligations, likewise forbidden moral acts should not be performed either. If performance of daily-prayers is compulsory and their non-performance is prohibited and brings Divine-Punishment, equally important is the fulfillment of a promise and its breach is prohibited and brings Divine-Wrath. The real religious and prosperous is some one who is committed to his religious obligation as well as is honest in fulfillment of his moral commitments. On the contrary ethics play an important role for achieving prosperity and spiritual perfection that will be explained in the book later on.
source : http://www.islamicecenter.com/e-library/logic_islamic_rules/logic_islamic_rules_makarem_subhani_03.html