In view of the fact that ethics is a branch of philosophy that studies good and bad moral traits, voluntary conducts and volitional behaviors, it is very much logical and scientific to discuss and put all moral traits together. The good moral traits are certainty, faith, tawakkul (consigning one's matters to God and trusting in Him) which are discussed along with self-conceit, selfishness, pride etc.  In addition, these traits are interlinked; faith and belief in God is the loftiest attribute of the nafs (soul) which has been greatly stressed upon but faith alone is not sufficient and it must bear certain qualities or conditions one of which is to do good deeds. Among the attributes which must be existent along with faith and religious belief is tawakkul and avoidance from pride, selfishness and self-conceit. It is only in the light of faith that man attains certainty and tranquility of the heart. Faith or belief should be accompanied with good deeds which would, on the one hand, help faith grow stronger and on the other hand, it would cause man to stay away from mean things and sins which form impediments in the way of perfection and growth of faith. In addition, there is no doubt that we need to know and distinguish moral virtues from moral evils, the good from bad.
Detailed answer:
Ethics is a branch of philosophy which addresses the objective claims of right and wrong, good and bad, and volitional behaviors which are characterized as either good or bad. It also shows connotes the method of acquiring good moral traits as well as doing good actions and avoiding bad moral traits and bad actions.[1]
The ultimate goal of ethics is to help man attain perfection and prosperity which is the real and main goal of the creation of the world and humanity. The real interpretation and materialization of perfection and prosperity is to manifest divine attributes as far as he can and as it lies within him. He should acquire good moral traits and act in such a way that he demonstrates divine attributes. While the world in its entirety is naturally and involuntarily engaged in glorifying God and praising His beauty and greatness, man should be, volitionally and of his own accord, the closest servant, the clearest and most perfect expression of God's attributes.[2]
Having said that, in ethics both good and bad traits and characteristics are discussed and studied and in view of this very fact, it is very much logical and scientific to discuss and put all moral traits together. These good moral traits are certainty, faith, tawakkul (reliance on God and trusting in Him) which are discussed along with pride, selfishness, haughtiness etc.
In order to clarify the relationship between these moral traits, we will endeavor to explain each one of the above traits as below:
A) Faith[3] and tranquility of the heart: In Islamic moral structure, faith and belief in God is the loftiest guiding attribute of the nafs (soul) which has been greatly stressed upon and it is for the same reason that we have been encouraged and persuaded to acquire the preliminaries of faith such as knowledge and certainty, however, faith alone is not sufficient and it must bear certain qualities or conditions. As per the Quran and prophetic traditions, one of the requirements of faith is to do good deeds. In most of them, good deeds have been mentioned immediately after faith. Faith without good deeds will not produce the required results and benefits. Hence, doing good deeds can be considered to be as one of the requirements of faith which will help produce the desirable benefits for the faithful. The Holy Quran says, "But whoever believes, and works righteousness,- he shall have a goodly reward, and easy will be his task as We order it by our Command."[4]
The Holy Quran says that he who claims to be a believer or a faithful person but he does not comply with God's order, he is making a false claim of faith: " They say, "We believe in Allah and in the messenger, and we obey": but even after that, some of them turn away: they are not (really) Believers."[5]
Therefore, according to Islamic ethics, claiming to be a faithful and believing Muslim without adherence to Islamic codes and divine commands, is false.  Among the acts which must be existent along with faith and religious belief is tawakkkul and avoidance from  pride, selfishness and ujb (self-conceit). It is only in the light of faith that man attains certainty and tranquility of the heart.
B) Tawakkul (reliance on God):[6] Another general concept in Islamic morality which is an attribute of the soul and which indicates a particular relationship between man and God is the concept of Tawakkul (trusting in God and consigning one's matters to Him).[7] What does tawakkul mean? Tawakkul is trusting in God and reliance on Him.  You trust in Allah's plan and accept whatever He decides, regardless of the results.  Hence, in tawakkul, you detach yourself from other powers.[8]
If such a state of trust and belief has to be acquired by man, one has to have a strong belief and conviction that there is no power independent of God and that there is none other than Allah Who creates, changes and affects the world. All other factors and causes are subjugated by Allah and operate under His Will. This is by itself one of the stages of tawhid (belief in the oneness of God).  Hence, tawakkul is rooted in the belief in one God and it is not achieved without one believing in His oneness. That is why some Muslim scholars have discussed monotheism and reliance on God together and they have written books under the title "al-Tawhid wa al-Tawakkul" to show that these two concepts are inter-connected.[9]
C) Self-conceit, selfishness and pride:[10] Self-love and selfishness are amongst the abominable traits which have been reproached in the traditions and is considered to be a great hindrance to religion and faith.  Imam Sadiq, peace be upon him, has been narrated as having said: "Jealousy, selfishness and taking pride are the plague of the religion."[11] The relationship between faith and moral evil is clear in this narration in the sense that jealousy, selfishness and taking pride endanger one's faith and belief in God. Sometimes, selfishness of the individual reaches a degree whereby he thinks that he has certain distinct characteristics or perfection which cause him to expect God to fulfill his demands. He believes that he enjoys a special place with God; he thinks that he has done a favor to God; whereas God Almighty has conferred a favor on him (by endowing him with faith). He considers it unlikely to face any evil incidents. This is in fact the highest degree of self-conceit and the meanest of them.[12]
Another thing which endangers man's belief in God is the feeling of proud of oneself. The Holy Prophet (S) said: "The plague of nobility is feeling proud of oneself and showing off (to others).[13]
Imam Baqir (A.S) said: "It is surprising of a person who shows himself off that he has been created of sperm and then he will be like a carcass and he himself does not know what will happen to him."[14]
Conclusion: Moral activities and adorning oneself with the good deeds and noble sayings cannot be done without staying away from moral evils. There is interconnection between moral virtues and evil traits. Faith or belief should be accompanied with good deeds which would, on the one hand, help faith grow stronger and on the other hand, it would cause man to stay away from mean things and sins which are impediments on the way to perfection and growth of faith. In addition, there is no doubt that we need to know and distinguish moral virtues from moral evils, the good from bad. Moral traits, good and bad, have been discussed together in the books written by Muslim scholars on morality and moral traits. These traits have been explained with reliance on the verses of the Holy Quran and Prophetic traditions.
 

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