Shaykh 'Abdul-'Aziz ibn Baaz rahimahullaah
From the book "Words Of Advice Regarding Da'wah"
Beware of being extreme
It is correct to name this awakening which pleases and excites every believer, an Islamic movement, an Islamic revival and an Islamic movement. It is necessary to encourage and guide this awakening towards adhering and clinging to the Qur'aan and the Sunnah of the Prophet Muhammad (sallallahu 'alaihi wa sallam) as well as warning leaders and individuals within this awakening from exceeding the limits, exaggerating and being extreme in their actions. In accordance with what Allah says in the Qur'aan, O people of the scripture, do not exceed the limits in your religion. [An-Nisaa 171] The Prophet Muhammad (sallallahu 'alaihi wa sallam) is reported to have said: "O you people, beware of being extreme and exceeding the limits in the religion, for that which destroyed the people before you was none other than extremism in the religion." He (sallallahu 'alaihi wa sallam) also said: "The extremists are destroyed, the extremists are destroyed, the extremists are destroyed."
Speaking about Allah without knowledge
Beware of speaking about Allah, the Most High, without knowledge. It is not permissible for one who believes in Allah, the Most High, and the Last Day to say: 'This is halaal and this is haraam' or 'This is permissible and this is prohibited', except with a proof and completely depending upon that. It should be sufficient for him to do what the people of knowledge did before him, and that is to restrain oneself from rushing into saying that which he does not know but rather to say: "Allah knows best" or "I do not know".
How excellent is the speech of the angels when they said to their Lord, Glory be to You, we have no knowledge except that which You taught us. [Al-Baqarah 32]
When the Companions of the Prophet Muhammad (sallallahu 'alaihi wa sallam) were asked about something that they did not know, they would say: "Allah and His Messenger know best." This is only because of the completeness of their knowledge and their faith and their glorification of Allah, and being far removed from embarking on matters beyond them.
Beware of accusing someone of disbelief or being sinful without proof
Indeed it is a most dangerous matter for one to dare to accuse some one of disbelief or of being sinful without proof and authorization from the Qur'aan and the Sunnah of the Prophet Muhammad (sallallahu 'alaihi wa sallam). There is no doubt that this is insolence towards Allah and His religion and it is also speaking about Him without knowledge. This is also in contradiction to the behavior of the people of knowledge and faith from among the pious predecessors, radiallaahu 'anhum. May Allah make us from amongst their followers in righteousness.
It has been authentically reported that the Prophet Muhammad (sallallahu 'alaihi wa sallam) said: "Whoever says to his brother, 'O kaafir!' It returns to one of them." He also said: "Anyone who called his brother 'O kaafir!' Or 'O enemy of Allah!' And it was not correct, it would return back to him." [Saheeh al-Bukhaari] i.e., whatever he said falls back on him. This is a strong threat, warning the people of accusing others of disbelieving and being sinful, except when they have sure knowledge and understanding. This and other evidences are also a warning that one should be careful to guard his tongue, and only say that which is good.
Beware of being hasty
How many calamities, difficulties and problems have afflicted those who are hasty! The days and nights are going and leaving behind the traces and consequences of hastiness! How much corruption and destruction and un-praiseworthy consequences have occurred because of partisanship and the following of desires? We ask Allah to keep us safe from that.
Beware of partisanship to a group
It is not permissible for one to blindly follow this person or that person, or the opinion of such and such a person. Nor should he follow blindly the methodology, or group of any individual.
Differing, It's Effects and Cure
There is no doubt that differing is one of the greatest trials and calamities to befall the Muslim Ummah. It is one of the reasons why efforts are being wasted and truth is lost. Differing among Islamic groups and Islamic centers, harms the Islamic da'wah. The only way that they can succeed is to have a unification of goals and is that they all exert their efforts and work together towards the goal which will secure the power and glory of Islam and the safety of the Muslims. It is necessary for every group, institution and community who want success in the Hereafter to help each other enjoin al-Birr (righteousness) and taqwa (piety). They should be sincere in their actions towards Allah and their primary concern should be the victory of Allah's deen, so that everyone can join together upon the truth and work upon what Allah has said in His Book,
Help you one another in al-Birr and at-Taqwa. [Al-Maaidah 2]
My advice for the daa'ees is that they should make sure that the actions should be done sincerely and purely for the sake of Allah, the Most High, alone. They should help one another in al-Birr and Taqwa and agree to rule by the Qur'aan and Sunnah whenever a disagreement breaks out amongst them, in accordance to what Allah says in the Qur'aan,
And if you differ in anything amongst yourselves, refer it to Allah and His Messenger if you believe in Allah and in the Last Day. That is better and more suitable for final determination. [An-Nisaa 59]
By this the goal will be one and the same and the efforts to search for success and warn away from following desires will be unified. Allah, the Most High, says,
But if they answer you not, they know that they only follow their own lusts, and who is more astray than one who follows his own lusts, without guidance from Allah? [Al-Qasas 50]
Allah says in the Qur'aan addressing His Prophet and His Messenger Daawood, 'alaihis-salaam,
O Dawood! Verily We have placed you as a successor on earth, so judge you between men in truth and follow not your desire, for it will mislead you from the Path of Allah.[ Saad 26]
Beware of Blind Support or Opposition Because Their Opinion Agrees or Conflicts With Yours
The deen of Allah must be the authority that judges everything. Beware of following your brother just because he agrees with you over an opinion and oppose another because he disagrees with you over an opinion or an issue. This is not being just or fair. We know that the sahaabah differed in issues, but this did not effect the good faith, support and love between them, radiallaahu 'anhum. So the believer acts by Allah's laws and he accepts and submits to the truth and he makes it precede everything else.
The believer should not oppress his brother, or act unjustly towards him if he differs with him over a opinion from the issues of Ijtihaad, in which the proofs may not be clear or issues in which there may be differing interpretations of the text. He may have an excuse, so you must advise him and love the khair (goodness) for him and do not allow the differing to induce and prompt aggression and discord between you. Do not enable the enemy to take advantage of you and your brother. And there is no movement or power except with Allah the Most High.
