The Prophet Muhammad (S) has said, “O' ‘Ali! There is repentance for every sin except for having a bad demeanor, since every time a person who has an unpleasant demeanor leaves one sin, he will enter into (another) sin.”[1]
In this tradition, the Noble Prophet (S) has pointed to the dangerous effect of having an unpleasant demeanor and has stated that, “People are able to ask repentance for all sins, however the person who has the characteristic and sin of an unpleasant demeanor will not be able to repent for this act as this trait never leaves a person.”
It is important to note that a person can repent for his sins and bad deeds, however the trait of having an unpleasant demeanor is not in itself an action that one can repent for.

The Effects of Having an Unpleasant Demeanor
1) Having an unpleasant demeanor is itself the source of many sins. A person who has this trait wishes to repent for his sin, however he ends up falling into another sin and thus, as the Prophet (S) himself has said, “This person can not ask for repentance.”
Thus, one of the effects of having an unpleasant demeanor is that a person would have multiple sins on his record such as annoying other people, lying, back-biting, oppression, etc…
2) Another effect of having an unpleasant demeanor is the societal effects. Thus, along with this trait, a person would gain the resentment of the people. Due to having a negative attitude, a person would end up losing his composure thus also losing his friends, support of the society and any influence he may have in society.
For example, a business man who possesses this trait may end up losing his clientele; a leader of the community may end up losing his followers!
In summary, having a negative disposition would lead to a person losing his friends and associates and it is even possible that such a person would lose his spouce and children!
What do we mean by a person “losing” certain individuals? This means that these people would be come strangers in his life and it may even reach a point that one's own children would not even like to see the face of their father since they know that their father has very bad etiquette! Thus, a separation would be created between the father and his children.
Therefore, another effect of having bad demeanor is other's disgust of the person and distancing themselves from one who has such negative traits.
3) The third effect this trait brings is the punishment of the soul and this would affect the person himself!
The person who has a negative demeanor actually ends up first off, annoying himself and then others!
Woe upon the fire of bad etiquette since it first ends up burning the inside of the one who who this trait and then burns those around the person! In addition, this trait would also produce physical illnesses and diseases and one would end up having a short life.

Reasons Why People Have a Bad Character
1) Great Expectations: When a person has many expectations, then naturally, times would come when there would be a divergence in what he wants to happen and what actually transpires and due to this, he becomes angry.
However if a person's expectations - even in relation to his family and those close to him was not so high, then he would definitely not become angry with things going on around him. Such a person would be ready to deal with such situations and would say, “I did not expect that to happen” or, “…anything can happen.” Thus, if one was to develop such a spirit within himself, then he would not become confused in the face of difficulties.
2) Pride and Conceit: Those who have pride would naturally like to position themselves above others and due to their innate disposition, other people do not get along with such individuals (who have pride and conceit) and try not to pay attention to them. Thus, when those who have pride and conceit see that what they want is not carried out, they become upset and display their bad character.
3) Inability to Forgive: There are some people who only forgive some things done to them and thus, they become aggravated very easily. However, we must ensure that we are able to forgive and forget everything that has occurred since if a one was to forget things which have happened to him, then he would develop a positive demeanor. The opposite of this statement is also true as if one did not practice the tradition of forgive and forget and was to always recall what happened to him in the past, then he would definitely get upset and in the end would develop the trait of having a negative demeanor!
4) Bad-Tempered and Irritable: A person who is bad tempered or irritable would not be able to deal with issues that come up in life. There is a famous proverb in Farsi which says: “He finds bitter raisins to be sweet and sweet raisins to be sour.” By this we mean that tranquility in his house is actually like a storm. Such people always possess a negative demeanor, bad ethical traits and are constantly grumpy. However, if a person was to be even-tempered and laidback, then he would be able to bear anything which comes up in life.
These are four spiritual or psychological traits which come about from a bad demeanor, however at this point we turn our attention towards the societal impact and the effects on the physical body.

The Societal Effects and the Outcome on the Physical Body
1) One who possesses a short temper would sometimes also develop a bad demeanor.
Have you noticed how sometimes, those who are physically sick also become very ill-mannered - why is this? It is because they are not able to withstand their sickness!
Thus, one must keep such a person's mental state in mind and refrain from yelling while in their presence as this would only serve to further aggravate them. The people who are taking care of such people must also be lenient with them and their attitude since the person who is physically sick is in such a state that his bad demeanor is actually natural and a part of being physically sick!
In the afternoons in the blessed Month of Ramazan, some people become extremely upset and display very bad etiquette and manners. Due to the effects of the hunger and thirst, their blood has become thick and is not able to reach to their brain. Their nerves become tired and their brain cells are not fed and thus, naturally, they become angry and are not able to control themselves.
Thus, in these sorts of situations, it is better for a person who is fasting to be in a place in which theose who are in a state of anger are less as a person is able to prevent himself from going to such places where people who are full of rage and anger are not and to also limit his interaction with such people at that time of day. Thus, he would seek to ensure that he is not in a place where the presence of people who possess a crooked demeanor would be manifest.
2) Sometimes if a person is refused something or treated in a bad way in one place, this may lead him to have a negative demeanor in another place. For example, if a person had some troubles in the shopping centre, when he steps into his house, he may begin to mentally torture his wife and children and may even physically beat them!
Therefore, having a negative demeanor is something very bad especially for those who are working around other people. Thus, in order to be able to have more a greater impact on the hearts of the people, we must not be the manifestation of the verse, which reads:

لَوْ كُنْتَ فَظًّا غَلِيظَ الْقَلْبِ لاَنْفَضُّوا مِنْ حَوْلِكَ

“Had you (O' Muhammad) been very harsh, then surely the people would have dispersed from around you…”[2]
Rather, we must be the manifestation of the portion of the verse which reads:

فَبِمَا رَحْمَةٍ مِنَ اللٌّهِ لِـنْتَ لَهُمْ

“So then it is from the mercy of Allah that you are lenient with them…”[3]
However as we know, those people who do not have continuous dealings with other people usually do not show bad etiquette and demeanor as they are not around people of various characters.
Thus in summary, we see that sometimes possessing a bad demeanor would destroy a person's entire life!
However, we should know that in addition to seeking to remove all of the things which result in this bad demeanor, we ourselves must also struggle and work to gain righteous etiquette.
It is interesting to note that Imam ‘Ali b. Abi Talib (as) was an individual with such a good demeanor that his enemies used to accuse him of one who jokes around too much!
In order for a person not to gravitate towards bad etiquette and morals, one must seek to instill good etiquette in all aspects of his life. He must work to have these noble traits mature within himself and must give importance to this aspect of his life.
In order to better understand how important having good morals is in the eyes of the great leaders of Islam, we present the following traditions from the Infalliables (as).

A Summary of the Exemplary Morals of the Prophet (S)
Even though the Prophet's (S) victory was through the assistance of Allah (SwT), however from the apparent aspect, it took shape due to various circumstances. One such reason, which is perhaps the most important is the attractive ethical traits he possessed. The lofty humanistic traits and noble ethics were emobided in him such that even the staunchest of enemies was influenced by him and was forced to submit to him, while his friends were intensely attracted to him!
Truthfully, if we refer to the Prophet's (S) etiquette and morals as one of his miracles, we would definitely not have overstated the fact! An example of this ethical miracle can be seen in the victory of Makkah.
When the blood-thirsty and revenge-seeking polytheists who were constantly working crimes and transgressions against the Muslims, and who for many years were working against the faith of Islam and the Prophet (S) were put face to face with the Muslims, we see that the Noble Prophet (S), going against what all of his friends and enemies thought he would do, ordered the Muslims to forgive all of the polytheists of Makkah and all of their crimes were forgotten! Through this act of his, the following verse of the Qur’an became manifest:

… وَ رَأَيْتَ النَّاسَ يَدْخُلُونَ فِي دِينِ اللٌّهِ أَفْواجاً

“…and you see people entering into the faith of Allah in groups…”
The books of commentary, history and even children's story books are full of events in relation to the good demeanor, forgiveness, mercy, altruism, self-sacrifice and consciousness of Allah (SwT) which the Prophet (S) showed.
However, it is enough to state that in the tradition from Husayn b. ‘Ali (as) it has been mentioned that he said, “I asked my father, the Commander of the Faithful, ‘Ali b. Abi Talib (as) about the characteristics of the life of the Prophet (S) and his etiquette and my father, in a very detailed manner, explained to me by stating…”
It has been mentioned in this long tradition that, “The Prophet (S) was always cheerful and smiling with those whom he was in the company with, and was always found to be gentle and soft-spoken. Never was he seen angry, hard-hearted, rude, foul speaking, picking the faults of other nor excessively praising anyone. Not a single person was ever was ever made to feel hopeless by him and anyone who entered his house did not leave disparaged.
There are three things which he kept away from in regards to his self: arguing with others, speaking too much and entering into things which were none of his business; there are two things which he kept away from in relation to the people: he never ridiculed or rebuked anyone and he never went forth to find the hidden mistakes and errors of the people. It is only in relation to that area in which the Divine reward of Allah (SwT) was possible did he speak.
When he used to speak, his words had such an impact on the hearts of the people that everyone present would remain quiet and would not move an inch. It is only when he stopped speaking and was silent did they begin to speak.
However it was also seen that while in his presence, those around him did not indulge in arguments or wrangling. Anytime a stranger or un-aware person began to speak with anger and asked him for something, he would bear that person's attitude with patience and would tell his companions, 'Anytime you see a person who has some need, ensure that you fulfill it.' He never cut anyone's speech short and rather, waited for the person to finish what he wanted to say.”
Yes! If these noble ethical traits and the Divinely granted persona of the Prophet (S) was not there, then the backwards, ignorant ‘Arab nation and the angry, hard-lined ‘Arabs would not have entered into the faith of Islam and would have been the manifestation of the verse which reads:

لاَنْفَضُّوا مِنْ حَوْلِكَ

“…they would have dispersed from around you…”
How good it would be that such Islamic etiquette is brought back to life today and that within the life of every single Muslim, the greatness which was exemplified in the morals and etiquette of the Prophet (S) are seen!
The Importance of Having a Good Demeanor According to the Islamic Narrations
The Islamic narrations, whether in regards to the Prophet (S) or in regards to the general responsibilities of all of Muslims are replete with words of guidance. At this point, we review some of these traditions.
1. The Prophet of Islam (S) has said:

إِنَّمَا بُعِثْتُ لِـأُتَمِّمَ مَكَارِمَ الأََخْلاَقِ

“I was raised up (as a Prophet) to perfect the ethical traits.”
Thus, one of the main goals behind the appointment of the Prophet (S) was to perfect the noble ethical traits.
2. In another tradition from the Prophet (S), it is mentioned that:

إِنَّمَا الْمُؤْمِنُ لَيُدْرِكَ بِحُسْنِ خُلْقِهِ دَرَجَةَ قَائِمِ اللَّيْلِ وَ صَائِمِ النَّهَارِ

“The true believer who possesses a good demeanor shall reach to the level of the person who stands up all night in the worship and fasts during the entire day.”[4]
3. In another tradition from the Prophet of Islam (S), he said:

مَا مِنْ شَيْءٍ أَثْقَلَ فِـي الْمِيزَانِ مِنْ خُلِقِ حَسَنِ

“Nothing is heavier in the scale (of good deeds) than having a good demeanor.”[5]
4. It has also been narrated from the Prophet (S) that he said:

أَحَبَّكُمْ إِلـى اللٌّهِ أَحْسَنُكُمْ أَخْلاقاً أَلْمَوْطُؤنَ أَكْنَافاً، أَلَّذِينَ يَأْلَفُونَ وَ يُؤلِفُونَ. وَ أَبْغَضُكُمْ إِلـى اللٌّهِ الْمَشَّاؤُونَ بِالنَمِيمَةِ، أَلْمُفَرِّقُونَ بَيْنَ الإِخَوَانَ، أَلْمُلْتَمِسُونَ لِلْبَرَآءِ الْعَثَرَاتِ

“The most beloved of you to Allah is the one who has the best etiquette; the one who is the most humble and modest; that person who is spiritually attracted to other people and whom others are also attracted to. The worst of you with Allah is the person who indulges in gossiping; the one who causes differences and divisions between brothers; and the person who tries to find faults in those who are free of error.”[6]
5. In another tradition from the Prophet (S) it has been mentioned that he said:

أَكْـثَرُ مَا يَدْخُلُ النَّاسَ الْجَنَةَ تَقْوى اللٌّهِ وَ حُسْنُ الْخُلْقِ

“The greatest of things which will permit a person to enter into Paradise will be his Consciousness of Allah (Taqwa) and his good demeanor.”[7]
6. In a tradition from Imam Muhammad b. ‘Ali al-Baqir (as) we read that:

إِنَّ أَكْمَلَ الْمُؤْمِنِينَ إِيْمَاناً أَحْسَنُهُمْ خُلْقاً

“Surely the most perfect of believers in true faith is the one whose demeanor and etiquette is the best.”[8]
7. In a tradition from Imam ‘Ali b. Musa al-Riza (as) we read that the Prophet (S) said:

عَلَيْكُمْ بِحُسْنِ الْخُلْقِ، فَإِنَّ حُسْنَ الْخُلْقِ فِي الْجَنَّةِ لاَ مَحَالَةَ، وَ إِيَّاكُمْ وَ سُوءَ الْخُلْقِ، فَإِنَّ سُوءَ الْخُلْقِ فِي النَّارِ لاَ مَحالَةَ

“I advise you all to have a good demeanor since the outcome of having a good demeanor is Paradise, and I warn you to keep away from having bad morals and etiquette since surely the outcome of this is nothing but the hell-fire.”[9]
From these traditions we can clearly see that having good etiquette and morals is the key to paradise; the way to attain the pleasure of Allah (SwT); a sign of the power of faith and is equivalent to the worship of Allah (SwT) day and night and the traditions which speak in this light are many!
On the other hand, a bad demeanor has also been mentioned in the Islamic narrations:
1. The Messenger of Allah (S) has said:

أَلْخُلْقُ السَّيِّءُ يُفْسِدُ الْعَمَلَ كَمَا يُفْسِدُ الْخَلُّ الْعَسَلَ

“A bad demeanour spoils good deeds just as vinegar spoils honey.”[10]
2. The Messenger of Allah (S) has also said:

سُوءُ الْخُلْقِ ذَنْبٌ لا يُغْفَرُ، وَ سُوءُ الظَّنِّ خَطيئَةٌ تَفُوحُ

“Bad etiquette and morals is a sin which will not be forgiven and having bad thoughts about another person is an error which spreads (to other people).”[11]
3. The Messenger of Allah (S) has also said:

إِنَّ الْعَبْدَ لَيَبْلُغَ مِنْ سُوءِ خُلْقِهِ أَسْفَلُ دَرَكِ جَهَنَّمَ

“Surely the servant (of Allah), due to his bad etiquette and demeanor, will reach to the lowest levels of Hell.”[12]
4. The Commander of the Faithful, ‘Ali b. Abi Talib (as) has said:

رُبَّ عَزِيزٍ أَذَلَّهُ خُلُقُهُ، وَ ذَلِيلٍ أَعَزَّهُ خُلُقُهُ

“How many times is it seen that a noble person is debased due to his demeanor while a low and humbled person is magnified due to his demeanor and etiquette.”[13]
5. The Commander of the Faithful, ‘Ali b. Abi Talib (as) has said:

مَنْ سَآءَ خُلُقُهُ فَأَذِّنُوا فِي أُذُنِهِ

“One whose etiquette is bad should have the Adhan proclaimed in his ear.”[14]!

Notes:
[1] Bihar al-Anwar, vol. 74, pg. 46
[2] Surat ale Imran (3), verse 159
[3] Ibid.
[4] Bihar al-Anwar, vol. 71, pg. 373
[5] Ibid., vol. 71, pg. 382
[6] al-Kafi, vol. 8, pg. 68
[7] Bihar al-Anwar, vol. 70, pg. 288
[8] Ibid., vol. 71, pg. 382
[9] Ibid., vol. 10, pg. 369
[10] Ibid., vol. 73, pg. 297
[11] al-Mahajjatul Bayda, vol. 5, pg. 93
[12] Ibid.
[13] Bihar al-Anwar, vol. 71, pg. 396
[14] Ibid., vol. 62, pg. 277