Al Imam Zain Al Abedeen says (a.s) says:” The right of the companion (sahib) is that you act as his companion with bounty and in fairness. You honor him as he honors you and you do not let him be the first to act with generosity. If he is the first, you repay him. You wish for him as he wishes for you and you restrain him from any act of disobedience he might attempt. Be a mercy for him, not a chastisement. And there is no strength save in God”.
When a man is busy with life's issues and accumulated with a number of problems that he’s facing, he needs a free space to rest in and renew his energy and needed eagerness.
Also when a man is isolated to plan for life issues when his feelings are in trouble with conflicting thoughts, then he needs another free space.
When a heart is distressed by problems, a man also needs a free space. This free space is a friend and brother for the sake of God.
It was narrated by Al Imam Al Sadeq (a.s):” Everything has a free place to rest in; a believer's free space is his faithful brother, same as when a bird rests with his similar friend”. 
Having a brother to please God is a divine blessing for the servant. It’s not valued by the world’s treasures. Neglecting this blessing is not less in value than neglecting the most valued blessings. Yes, it is so because those who passed through such experiences know that losing a friend leads to tiredness, sleeplessness and regret.
Why do we Acquire Friends?
A social person should acquire an irreplaceable friend in life’s crowd. Yes, a friend is the closest person to his friend, he helps him in times of distress and listens for him where there’s no one else. Therefore, the prophet’s family (peace be upon them) insisted on acquiring as many friends as possible. It was narrated by Al Imam Ali (a.s):” Try to have as many true friends as possible, for they are the supplies in joy and the shelters in misfortunes.”. 
The prophet Mohammad (pbuh) says:” The believers in their mutual kindness, compassion and sympathy for the sake of God are just like one body. When one of them suffers a pain in an organ, his friend responds to it by feeling pain in the same organ”. 
But also having friends is beneficial for the hereafter not only in life. The prophet Mohammad (pbuh) says:” One who takes up a friend to please God (SWT), has reserved for himself a house in Paradise”. 
This is added to the benefits manifested in the hereafter through being granted intercession where a brother intercedes for his brother and a friend intercedes for his friend. This is the most valued benefit that a man can get on the day whereon neither wealth nor sons will avail. The prophet Mohammad (pbuh) says:” Acquire more and more friends because on the Day of Judgement each believer shall exercise his right of intercession (shafa'at). 
Do not Neglect your Brother
Because of all of the mentioned importance, we shouldn’t ignore our friends and brothers acquired to God. Because of that importance also we should take into account the feelings of friends to keep up friendliness between them. We will shed light on issues that damage friendliness and what we should prevent as much as possible to keep up this divine blessing.
Preventing Harm, Al Maaref Islamic and Cultural Institution
 Bihar Al Anwar, Al Allama Al Majlisi, part 74, page 234
 Mizan Al Hikmah- Mohammad Al Rishhari- Hadith 155.
 Bihar Al Anwar, Al Allama Al Majlisi, part 74, page 280
 Mizan Al Hikmah, Mohammad Al Rishahry, Hadith 158.
 Mizan Al Hikmah, part 1, Mohammad Al Rishahry, page 39.