Source: The Islamic Awakening, Pgs. 67-71, by Shaykh Muhammad bin Saalih al-‘Uthaymeen [d.1421H], Translated by Faisal ibn Muhammad, Published by Al-Hidaayah Publishing & Distribution
The youth who adhere to their Religion and are concerned with the da’wah should have open minds and hearts regarding differences of opinion among the scholars, finding a good excuse for the scholar who supports a view, which in their mind, is wrong. This is an issue of paramount importance, for there are those who search out for and scrutinize the mistakes of others, with the intention of ruining their reputation, and this is from the greatest of mistakes. If backbiting a common man [i.e., one who is neither a scholar nor a student of knowledge] is from the gravest of sins, then backbiting a scholar is graver and more severe. The harm of backbiting a scholar is not limited to his person, but it also extends to the Islamic knowledge he carries with him. If a scholar is lowered in the eyes of the people, what he says is also lowered. So if he speaks the truth and guides others to it, then backbiting him acts as a barrier between the people and the knowledge he has with him. And the danger involved in this occurring is considerable.
It is necessary for the youth to attribute good intentions to scholars when there is disagreement among them. At the same time, there is no harm for the youth to go to a scholar they think made a mistake, and discuss the matter with him, for it may happen that that scholar will be able to show them that he was in the right all along. Often times one imagines that a scholar erred, but after discussing the issue with him, one comes to realize that he was right.
“Everyone from the children of Adam errs frequently, and the best of those who err frequently are those who repent.” 
When people begin to rejoice over the mistakes of the scholars, spreading news of those mistakes to the people, discord and disunity will result, and that is not the way of the pious predecessors.
Likewise, in the case of rulers: it is not permissible for us to use their mistakes as a pretext for vilifying them in a general way, and yet remain blind to their good qualities and actions. Allaah [subhaanahu wa ta’aala] says in His Book:
“O you who believe! Stand out firmly for Allaah [subhaanahu wa ta’aala] and be just witnesses and let not the enmity and hatred of others make you avoid justice.” [Al-Ma’idah 5:8]
This means: do not let the hatred you have for a people lead you to being unjust, for justice is compulsory. And it is not permissible for one to take the mistakes of rulers, scholars, or anyone else for that matter, and then spread news of those mistakes to the people, while remaining quiet about their good qualities and deeds. This is not justice.
Always use yourself as a gauge in such matters. If one were to spread news of your bad qualities to the people and hide your good qualities, you would say that he committed a crime against you. If that is your attitude regarding your own self, then you must maintain the same attitude regarding others as well. I already mentioned the solution to this problem: contact the person you think made a mistake and directly discuss the issue with him, and then matters should become clearer [to you or to him] after the discussion.
How often it occurs that one rescinds one of his opinions after discussing it with someone else:
“The example of a believer in relation to another believer is that of a building; parts of it strengthen its other parts.” 
And the Prophet [sall-Allaahu ‘alayhi wa sallam] said:
“Whomsoever it pleases to be taken away from the Hellfire and to enter Paradise, then let his death come to him while he believes in Allah and the Last Day. And let him take [or give] to the people that which he loves to come to him.” 
This is justice and uprightness
The heart of the caller should be open to those who differ with him, especially when he knows that the other party has good intentions, differing only because of some proof he considers to be stronger. One must be flexible in such matters, not allowing differences of opinion lead to enmity and hatred between brothers, except in the case of a man who is obstinate in his view: the truth becomes clear to him, yet he persists upon his falsehood. Such a person should be warned against; his enmity to the truth became established when the truth became manifestly clear before him, yet he still refused to follow it.
Nevertheless, we must make a distinction here: there are secondary issues that people differ in, and in reality, Allaah [subhaanahu wa ta’aala] made such matters in such issues wide and spacious for His slaves; here I am referring to issues that are not from the primary teachings of the Religion; those teachings regarding which the one who opposes is ruled to be a disbeliever. Other than those primary teachings, Allaah [subhaanahu wa ta’aala] made matters spacious for His slaves; the Prophet [sall-Allaahu ‘alayhi wa sallam] said:
“When the judge rules after making Ijtihad [using all resources – proofs and sound principles of deduction – available to him in order to arrive at a ruling], and is then correct, then he has two rewards. And if he is mistaken, then he has one reward.” 
In any case, whether he is wrong or right, the judge is rewarded, with two rewards if he is right and with one reward if he is wrong.
If you do not want anyone to differ with you, keep in mind that every other person also does not want anyone to differ with him. And Allaah [subhaanahu wa ta’aala] clarified the returning point for any disagreement:
“And in whatsoever you differ, the decision is with Allaah [subhaanahu wa ta’aala] [He is the ruling Judge].” [Ash-Shura 42:10]
And Allaah [subhaanahu wa ta’aala] said:
“[And] if you differ in anything amongst yourselves, refer it back to Allaah [subhaanahu wa ta’aala] and His Messenger [sall-Allaahu ‘alayhi wa sallam], if you believe in Allaah [subhaanahu wa ta’aala] and in the Last Day. That is better and more suitable for final determination.” [An-Nisa 4:50]
Whenever two parties disagree among themselves, they must defer to these two primary sources – the Book of Allaah and the Sunnah of Allaah’s Messenger [sall-Allaahu ‘alayhi wa sallam]. It is categorically forbidden to oppose the speech of Allaah and His Prophet [sall-Allaahu ‘alayhi wa sallam], no matter whose speech it is that one is giving preference to. When the truth becomes clear to you, it is incumbent upon you to “strike the saying of anyone who opposes that truth against the side of a wall,” and you must never look back at that saying, no matter how high the status and knowledge is of the person who said it. Human beings err, but there is not a single error in the speech of Allaah and His Messenger [sall-Allaahu ‘alayhi wa sallam].
It greatly saddens me to hear that some people who are considered to be serious in their pursuit of the truth, are divided, with each one of them taking on a different title or descriptive quality. In reality, this is a serious mistake, for Allaah’s Religion is one, and the Ummah [Nation] of Islam is one. Allaah [subhaanahu wa ta’aala] says:
“And verily! This, your religions is one religion, and I am your Lord, so keep your duty to me.” [Al-Mu’minun 23:52]
And Allaah [subhaanahu wa ta’aala] said to His Prophet, Muhammad [sall-Allaahu ‘alayhi wa sallam]:
“Verily, those who divide their religion and break up into sects, you [O Muhammad [sall-Allaahu ‘alayhi wa sallam]] have no concern in them in the least. Their affair is only with Allaah [subhaanahu wa ta’aala], Who then will tell them what they used to do.” [Al-An’am 6:159]
And Allaah [subhaanahu wa ta’aala] said:
“He [Allaah [subhaanahu wa ta’aala]] has ordained for you the same religion which He ordained for Nuh, and that which We inspired in you [O Muhammad [sall-Allaahu ‘alayhi wa sallam]], and that which We ordained for Ibrahim, Musa and ‘Isa saying you should establish religion and make no divisions in it [religion] [i.e. various sects in religion].” [Ash-Shura 42:13]
Because this is the guidance of Allaah [subhaanahu wa ta’aala], we must follow and implement it. We must gather and discuss issues in order to improve and rectify our situation, and not in order to accuse another or exact retribution from one another. Whenever one debates an issue with another person, intending to achieve victory for his view and to belittle the view of his opponent, without intending betterment, then for the most part, he will leave the debate in a way that does not please Allaah and His Messenger [sall-Allaahu ‘alayhi wa sallam].
In matters of discord, we must truly become one Nation. I am not saying that no one makes mistakes; people are sometimes right and sometimes wrong in their views. But what we are discussing here is how to rectify and mend what is wrong. I am not helping to change a person’s incorrect view by backbiting and slandering him. The way to help him is to meet him and to discuss the situation with him, and if he stubbornly persists in his falsehood, I then have the right, or rather the duty, to clarify his mistake and to warn people against it. And by following this methodology, we can help improve matters.
As for division or the forming of factions, this is something that pleases no one save the enmeies of Islam and of Muslims.
 Related by Ahmad in his Musnad [3/198]; by Al-Darimi  in the chapter, “About Repentance.” Al-Tirmidhi related it  in chapter 49, Ibn Majah  related it in the chapter, “About the Mention of Repentance.” In Sahih al-Jami’ [4/171], Al-Albani related that it is hasan. In Sharh al-Sunnah [5/92], Al-Arna’ut said, “Its chain is hasan,” from the hadeeth of Anas [radee Allaahu ‘anhu]
 A portion of a hadeeth related by Al-Bukhari  in the chapter, “The Believers Cooperating with one Another.” Muslim  related in the chapter, “The Mutual Mercy, Compassion, and Help of the Believers,” from the hadeeth of Abu Musa Al-Ash’ari [radee Allaahu ‘anhu]
 A portion of a hadeeth related by Muslim  in the chapter, “It is Compulsory to be Faithful to One’s Pledge to the Khalifah…” from the hadeeth of ‘Abdullaah ibn ‘Amr ibn Al-‘As [radee Allaahu ‘anhu]
 Related by Al-Bukhari  in the chapter, “The Reward of a judge when he makes Ijtihad…” And Muslim related it  in the chapter, “Clarification of the Judge’s Reward when he Makes Ijtihad…” from the hadeeth of ‘Amr ibn Al-‘As [radee Allaahu ‘anhu]