The responsibilities of a Muslim towards family, relatives and other Muslims in general, were already reviewed in an article. Here one's responsibility in Islam towards neighbors, friends, and enemies are discussed.

The Responsibility in Islam Towards Neighbors 

Doing good to neighbors is highly emphasized in Islamic teachings: “Worship Allah and … be good to … the near neighbor and the distant neighbor” (4:36). Prophet Muhammad (PBUH&HP) advised Imam Ali (AS) to honor the neighbors, even if they are disbelievers (Kafir) [1]. Imam Ali (AS) said that Prophet Muhammad (PBUH) used to invite repeatedly to doing good to neighbors such that we thought he (PBUH) was going to consider an inheritance for them [2].

The rights of neighbors on one another as an important responsibility in Islam, are:

To honor them in their presence, and to help and care about them when they are absent [3]. It includes visiting neighbors when they are sick, to assist their funeral, and to offer them your tasty meals that smell good [4];
To keep their secrets. It means that not to look for their faults and errors. And, if ever you become aware of some of their faults, do not reveal them but try to conceal their deficiencies [3];
Do not leave neighbors alone in difficulties [3]; e.g., help them in case of financial needs [4];
Do not be jealous of them if God grants them some blessings [3];
Ignore their errors to yourself and forget about them. If ever they do wrong to you unintentionally, be patient and in peace with them [3];
Do not let others talk behind their back and reveal the deficiencies of your neighbors here and there [3].
Giving priority to the neighbors. It is narrated from Imam Hassan (AS) that Lady Fatima al-Zahra (AS) used to pray firstly for the neighbors and then for members of the family [5]. 

According to Imam Sadiq (AS), having good behavior and interaction with neighbors increases the provision (Rizq) [6]. Prophet Muhammad (PBUH) advised to respect neighbors as much as one should respect his\her mother [6] and he (PBUH) said: “God bless whoever does good to his\her neighbors” [7]. On the contrary, whoever sleeps peacefully at night while one of the his\her neighbors is hungry, God will deprive him of his blessings on the judgment day [8]. The same will happen to whoever annoys his\her neighbors [1]. 

Take your time and think about these attitudes towards the neighbors. Life will be surely much agreeable and peaceful if we improve our social interactions with our neighbors within the Islamic framework.

The Rights of Friends and Companions

Having a good companion is known as a blessing; on the contrary, a bad one is like a disaster [9]. Friends and companions have certain rights one over the other including:

To interact with them with generosity as much as you can, otherwise, be fair to them [3];
To be smiling when you meet them and to receive them modestly [3];
To respect them as they respect you [3];
To be the first one who does good to the other one, otherwise, try to compensate properly [3];
To help them in difficulties and whenever they are in need, as Imam Ali (AS) advised to [10];
To hold them in great affection according to Imam Ali (AS) [11];
Not to reveal their deficiencies and mistakes;
To encourage them in obedience to God and to prevent them from committing sins [3];
To be honest with them and not to cheat [3]; e.g., nor to talk behind their back neither to reveal their deficiencies and to guard their secrets;
To be trustworthy whenever they rely on you [3].

The Responsibility in Islam Towards the Enemies

The enemy here means a person whom one is in conflict with. There are some recommendations in Islamic resources on how to treat enemies and what is one's responsibility in Islam towards them:

To be fair with them [12]. According to Imam Sadiq (AS), a real believer (Mu'min) does not oppress his\her enemies [13];
To testify in favor of the enemies if they are right [14] even if your testimony is against yourself [3];
To keep the promises you made to your enemies [15];
To forgive and tolerate them, if possible [3]. According to Imam Ali (AS), there is a virtue in forgiving enemies [16];
To talk nicely and shortly with whoever you have complained of [3], to argue with them in a way that is best (16:125), and not to ignore their rights if ever you are wrong [3].

References:

1. M. Shoueiri “Jami’ al-Akhbar”, p. 84.
2. Shaykh al-Kulayni, “Al-Kafi”, vol. 7, p. 51.
3. Imam Zayn al-'Abidin (AS), “Treatise On Rights (Risalat al-Huquq)”.
4. responsibility towards others
5. Shaykh al-Saduq, "Ilal Al-Shara'i", p. 181
6. Shaykh al-Kulayni, “Al-Kafi”, vol. 2, p. 666.
7. Shaykh al-Saduq, “Al-Amali”, p. 288.
8. Shaykh al-Kulayni, “Al-Kafi”, vol. 2, p. 668.
9. “Ghurar al-Hikam wa Durar al-Kalim”, T. 4719-4720.
10. “Nahj al Balaqa”, p. 494.
11. “Ghurar al-Hikam wa Durar al-Kalim”, T. 9665.
12. Ibn Shu’bah, “Tuhaf al-Uqul”, p. 88.
13. Shaykh al-Kulayni, “Al-Kafi”, vol. 1, p. 47.
14. Shaykh al-Saduq, “Sifat al-Shia”, p. 24.
15. “Nahj al Balaqa”, p. 53.
16. “Ghurar al-Hikam wa Durar al-Kalim”, p. 435.

One of the features of a believing Muslim is that he/she always wants to grow closer to Allah and constantly seeks His satisfaction. For this reason, there are numerous narrations from the infallible Imams (A.S) indicating the right time and place for seeking closeness to Allah.It is clear that God is the Most Gracious, and his Mercy is always bestowed upon humankind wherever they are. However, there are special times and places at which God’s benevolence towards His creatures becomes even greater. One of these occasions is the Day of Arafah.

When is the Day of Arafah?

The ninth day of Dhu al-Hijjah (the final month of the Islamic lunar calendar) is the day of Arafah when Hajj pilgrims stand on the plain of Arafat (a vast desert about 20 km southeast of Mecca) to pray. Arafah can be translated as knowing, understanding or theosophy [1]. 

According to historians, it was on the plain of Arafat where Adam and Eve met each other once again after their descent from heaven and long separation upon the Earth, and their sins were forgiven by Allah.
It also recalls how Gabriel taught the prophet Abraham (AS) all the Hajj rituals on the plain of Arafat.

The day of Arafah is so important that Imam Hussain (AS), the third infallible Shia Imam, recited the famous supplication of Arafah one year during his pilgrimage to Mecca on this day.

The virtues of the Day of Arafah

Arafah is one of the most blessed days in Islam that carries a lot of merits for the ones who are present on the plain of Arafat and other people elsewhere. This day in its blessedness and sacredness weighs the same as the Night of Qadr. It has been narrated, “People who were not able to achieve their purpose in the Night of Qadr or those who were not forgiven on that day, Arafah is the last opportunity for them” [2].

So, many Muslims occupy themselves with reciting the Holy Quran, prayer, and supplications hoping that there would be more opportunities for them to be forgiven by Allah on this special day. One of the best deeds performed by Shia Muslims is reciting Imam Hussain’s (AS) supplication of Arafah, which best represents the spirit of this day. Contemplation on this amazing supplication which encompasses facts about monotheism and its degrees will ultimately bring us closer to Allah.

The supplication of Arafah by Imam Hussain (AS)

In this supplication, we first praise God in a loving and friendly manner. Then we count the blessings God has bestowed upon us, and after confessing our misdeeds and sins, we ask Allah to forgive them. That is when we put forth our request to God. Now let’s recite and think about some of the most beautiful verses from this supplication (Dua): (You may also find the audio and the English subtitle of this supplication here.)

Arafah, a better opportunity to praise Allah

“Praise be to Allah Whose determination cannot be repelled by anything, whose gifts cannot be stopped by anything, and Whose making cannot be resembled by the making of anyone. He is the All-magnanimous, the All-liberal.”

A Path to Self-knowledge

“Even before that (before you showed me the right path), You had compassion on me, through Your excellent conferral and Your affluent bestowals. So, You fashioned my creation from semen that gushed forth and put me up in triple darkness among flesh, blood, and skin. You have not made me witness my creation, and You have not referred any part of my creation to me.”

Getting trained at the Divine school of God

“So, Exalted be You, O All-merciful, O All-beneficent. When I commenced (my life) by pronouncing words, You perfected for me the affluent bestowals and brought me up to an increase every year. When my creation was accomplished, and my power became straight, You put me under the obligation of Your Claim, which is that You inspired me with recognition of You and alarmed me by the wonders of Your wisdom.”

Counting God’s blessings

“As You created me from the best of soil, You, my God, have not wanted for me to have a certain favor (and to be deprived of another) and You, therefore, provided me with the various kinds of living and types of wealth, out of Your great and grand conferral upon me, and Your eternal kindness to me.”

Testimony to the boundless Divine blessings

“And I bear witness, O my God, with my true belief, and the fortitude of the determinations of my conviction and the purity of my open belief in Your Oneness and the essence of the secret of my conscience, and the ties of the canals of the light of my sight, and the lines of my forehead and the hallows of the courses of my breath, and the (nasal) cavities of my nose, and the courses of the meatus of my hearing, and whatever my two lips hide and cover up, …”

Human inability to thank Allah

“I bear witness) that if I try my best and strive throughout all ages and at all times, if I live them, to thank properly only one of Your favors, I will not be able to do that, except through a favor of You, which also requires me to thank You for it, once again with new thanking and with praise that is newly acquired and newly prepared.”

The opportunity to repent and ask for forgiveness

“It is I who did wrong. It is I who had evil intention…I now acknowledge of my sins; so, (please) forgive them to me.”

Arafah is one of the best days to turn to God with sincere repentance. Allah, on this day, accepts the repentance of His servants and grant them forgiveness if they are truly regretful and determined to give up their sins.

The demands of a nobleman

“O Allah, (please) make me fear You as if I can see You. Make me happy by fearing You. Do not make me unhappy by disobeying You. Choose for me through Your decree. so that I will not long for hastening that which You have delayed or delaying that which You would hasten.”

Eventually, you will find yourself immersed in the ocean of Allah’s mercy, which is what a true believer always seeks.

 “O Allah, Verily, You are the nearest of those who are prayed, You are the promptest of those who may respond, the most generous of those who may pardon, and the most responding of those who are asked. O All-beneficent of the world and the Hereafter, and All-merciful!”

References:

1. Arafah
2. Day of Arafah
3. Arafah supplication
4. supplication