Allah tells us that He will place affection (wudd) between the hearts of those who believe and practice, saying:
{Inna alladhina aamanoo wa 'amiloo as-saalihaati sa yaj'alu lahum Ar-Rahmaanu wuddan.}
{Surely, as to those who believe and do acts of righteousness, the Most Merciful will make affection for them.} Maryam: 96
Brotherhood (ukhuwwa) is the connection between souls and the bonds between the hearts. It is a bond of faith which is based on Allah's program of living and grows out of piety and fear of Allah. Brotherhood is holding tight, all together, to the rope of Allah Most High. Brotherhood is peace and security. Its absence is fear and confusion, stagnation and conflict.
About this, the Prophet (sas) said in a sahih hadith:
"When Allah loves someone, He announces to Jibreel: "Surely, I love so-and-so, so love him also." And so Jibreel loves him too. Then, Jibreel calls out to all the inhabitants of Heaven: "Surely, Allah loves so-and-so, so love him. Then, all of the inhabitants of Heaven love him. Then, acceptance is provided for him in the earth."
So, Allah made affection for them because they loved Allah and so He placed affection for them in the hearts of His other righteous servants. As for the wicked of heart, there is nothing in their hearts but contempt and enmity for the righteous servants of Allah. They fight them at every turn, slander them and attempt to turn others against them. This is a sunnah of Allah which can be witnessed everywhere among the Muslims.
Brotherhood goes hand in hand with iman (belief). Allah brought us together with belief in ways not possible without it. And, when our belief becomes weak, brotherhood suffers. Allah said:
{Wa i'tasimoo bi habli Allahi jamee'an wa laa tafarraqoo wa idhkuroo ni'mata Allahi 'alaikum idh kuntum a'daa'an fa allafa baina quloobikum fa asbahtum bi ni'matihi ikhwaanan...}
{And hold fast to the rope of Allah all together and do not divide yourselves. And remember the favor of Allah upon you when you were enemies and He joined your hearts together and so you became, by His great favor, brothers...} Aal 'Imraan: 103
Although iman raises our state and increases the brotherhood and affection between the hearts of the believers, it will continue to be imperfect in this life due to human weakness and weakness in our Islam. Very many verses and hadith stress the necessity of various attitudes which help compensate for these human weaknesses. Among them are husnu adh-dhanni (ALWAYS assuming the best possible construction of another Muslim's deeds or statements, as-sitr (concealing the faults of another when they become known to you and not following the urge to spread them around), al-'afw and as-safh (forgiving, forbearing and overlooking and bad deeds or behavior from your fellow Muslim.
Nonetheless, the perfect brotherhood will only come for the believers in paradise. Allah said about them:
{Inna al-muttaqeena fiy jannatin wa 'uyoon. Udkhuloohaa bi salaamin aamineen. Wa naza'naa maa fiy sudoorihim min ghillin, ikhwaanan 'alaa sururin mutaqaabileen.}
{Surely, the pious will be among gardens and springs. Enter it in peace and security. And We will remove and ill-will which is in their hearts. Brothers, resting on sofas and facing one another.} Al-Hijr: 45-47
Brotherhood is peace and security just as its opposite is fear and difficulty. This brotherhood between the believers benefits us in this life and in the hereafter. Umar (ra) said:
"Encountering your brothers lifts all grief. If Allah blesses you with good relations with another Muslim, hold fast to it."
About brotherhood, Ali ibn Abi Talib said:
"Pay attention to your brothers for they are your provision in this life and in the hereafter. Do you not listen to the cry of the people of the fire? {So we have no one to intercede for us nor any dear friend.}" The verse he recited is Ash-Shu'araa: 100-101.
Believers are inherently brothers even in this life based on their iman and their love for Allah, but in this life it requires a constant struggle against our selves to actually practice what Allah has blessed us with and to make peace when differences occur based on Islam. Allah said:
{Innamaa al-mu'minoona ikhwatun fa aslihoo baina akhawaikum wa ittaqoo Allaha la'allakum turhamoon.}
{Surely, the believers are brothers, so make good that comes between your two brothers and fear Allah that perhaps you may be shown mercy.} Al-Hujaraat: 10
Man has been created with a physical nakedness which is more pronounced than any of Allah's creation and so Allah has ordered us to cover that nakedness and gave us the knowledge and the ability to manufacture clothing to cover this nakedness and to protect us from heat and cold and from each other.
Likewise, our souls are susceptible to evil desires such as envy, hatred, racism, nationalism and desire for power. For this spiritual nakedness, Allah has also given us a spiritual clothing to cover it and reduce its harm and its ugliness. This covering is taqwa or fear and awareness of Allah Most High. Allah made this analogy between the two forms of nakedness and the two forms of clothing in the following:
{Yaa banee Aadama, qad anzalnaa 'alaikum libaasan yuwaaree sau'aatakum wa reeshan. Wa libaasu at-taqwaa dhaalika khairun. Dhaalika min aayaati Allahi la'allahum yadh-dhakkaroon.}
{O sons of Adam, we have sent down for you clothing to hide your nakedness and clothing for beauty. But the clothing of piety is better. That is one of the signs of Allah that perhaps they may gain in consciousness.} Al-A'raaf: 26
Furthermore, this love between the slaves of Allah transcends the centuries and the generations. A believer must bear love for the believers of all ages and especially those from the best generations this world has ever seen: the generation of the Prophet (sas), i.e., his companions (May Allah be pleased with them) - ALL of the companions as well as the generation after them and the generation after that. Believers are commanded to make du'a for all other believers from all other times and places. In this way, the believers benefit one another, even across generations and places. Allah said:
{Wa alladhina jaa'oo min ba'dihim yaquloona rabbanaa aghfir lanaa wa li ikhwaaninaa alladhina sabaqoonaa bi al-imaani wa laa taj'al fiy quloobinaa ghillan lilladhina aamanoo rabbanaa innaka ra'oofun raheemun.}
{And those who came after them say: Our Lord! Forgive us and forgive our brothers who came before us in faith and do not place in our hearts any ill-will toward those who believe. Our Lord! You are the Compassionate, the Merciful.} Al-Hashr: 10
Iman includes harboring goodwill toward all other believers, defending them and defending their name always thinking of them in the best way possible and overlooking their faults concealing them if possible and asking Allah to forgive them and us. The Prophet (sas) said:
"Al-Muslim akhu al-muslim laa yadhlimuhu wa laa yuslimuhu wa man kaana fiy haajati akheehi kaana Allahu fiy haajatihi, wa man farraja 'an muslimin karbatan farraja Allahu 'anhu karbatan min kirab yaumi al-qiyaamati wa man satara musliman satarahu Allahu yauma al-qiyaamati."
"Every Muslim is a brother to every Muslim. He does not oppress him nor turn him over. Whoever addresses his brother's needs, Allah addresses his needs. Whoever relieves a Muslim from some hardship in this life, Allah will relieve him from a hardship onQiyama. Whoever conceals [the faults of] another Muslim, Allah will conceal [his faults] on the day ofQiyama."Muslim and Bukhari
To achieve this, Muslims must pay attention to one another, visit one another and be aware of each others needs and problems. The Prophet (sas) has given us many teachings which direct us to all that will foster brotherhood and warning us about all that which will destroy brotherhood. Examples:
"Man 'aada mareedhan au zaara akhan lahu fiy Allahi naadaahu munaadiyaan: tibta wa taaba manshaaka wa tabawwa'ta min al-jannati manzilan."
"Whenever someone looks in on a sick person or visits their brother in Allah, two callers call to him saying: You have become good and your road is good and you have prepared for yourself a place of rest in paradise." At-Tirmidhi"Laa yu'minu ahadukum hattaa yuhibbu li akheehi maa yuhibbuhu li nafsihi."
"None of you has believed until they love for their brother that which they love for themselves."Muslim and Bukhari"Man kaana yu'minu bi Allahi wa al-yaumi al-aakhir fal yaqul khairan au li yasmut. Man kaana yu'minu bi Allahi wa al-yaumi al-aakhir fal yukrim jaarahu. Man kaana yu'minu bi Allahi wa al-yaumi al-aakhir fal yukrim dhaifahu."
"Whoever believes in Allah and the Last Day let him speak that which is good or let him keep quiet. Whoever believes in Allah and the Last Day, let him honor his neighbor. Whoever believes in Allah and the Last Day, let him honor his guest." Muslim and Bukhari