In the name of Allah
Sectarianism in Islam: 

Unlike the Middle Eastern and Indo-Pak societies, many of us live in cosmopolitan towns and cities. Hence, there is diversity in attitudes, interests and more specifically ideologies: beliefs, thoughts and concepts. There is not one kind of Muslim with one school of thought etc. This has given birth to many disputes. Today it does not suffice to say ‘I’m a Muslim’ without adding a label or attaching yourself to a certain sect.
A problem then arises when the layman gets exposed to this, especially from those who are uneducated in Islam, he will either add fuel to the fire out of ignorance or distant himself from the ‘warmongers’, i.e. the ‘scholars’ hence further away from Islam to the extents of leaving the religion. I have personally encountered students asking in a negative light; “Why is there so much Ikhtilaf (differences) in Islam?” or “What doesn’t have Ikhtilaf?” (erm, the five pillars. Or is it four?) This can simply be pushed aside by saying ‘it’s a lack of knowledge and he’ll learn’. He can learn, but what about the busy layman who doesn’t get this opportunity besides browsing on YouTube during break for some inspirational speech and ends up viewing ‘Why such and such person/group is deviated!’ More importantly, what is the root to this problem?
In such diverse society, there is an unparalleled need to promote the good teachings of Islam, set aside the differences, and accept plurality. That being said, we cannot be superficial about it by presenting this plurality in a shallow manner as if we are living in the best of generations. This would most probably fail. Rather we need to assess the reality. There is deviance in our societies, but this does not necessitate the Takfir card nor does it mean to be violent to the ‘other sect’. There are different levels of sectarianism, of which some are currently acceptable for example in Fiqh and this is supposedly unique to our Faith tradition. (Although I can expand on this matter from a theoretical perspective, I do not want to digress too much from the purpose of my writing.) 
In identifying the causes to the problem, lack of education is number one. It is undeniable that a good quality of Islamic education will broaden your mind. Then again, this isn’t so true when you learn of a ‘cult’. Meaning, if you have information bias, the expected results would not be achieved; rather it would lead directly to the problem. A point to be made here is that the masses do not have basic knowledge, so in hunt for answers they will search Shaykh Google. Evidently, there’s open access to a lot of information but how can a layman process this information correctly without the basic knowledge of telling right from wrong (while everybody’s mind works differently) and consequently ‘creating his own school of thought’ or becoming his own ‘Mufti’. Understandably, the solution is to find a person with knowledge that you trust. On the other hand, it also means this ‘scholar’ cannot play the guilt trip giving unsatisfying answers as though the knowledge is restricted to the scholars. A general teaching of Islam is to be able to ask critical questions. فاسألوا أهل الذكر إن كنتم لا تعلمون
This brings me to the next cause of the problem, the absence of qualified leadership. It is essential for communities to commit to train and develop leadership from the youth. Some make scholarship so ‘inaccessible’, as if you have to travel overseas and study many endless years or you don’t have a right to touch knowledge. Although this is something more associated to the past, the ‘scholarly class’ has also faced a backlash of aversion in the Catholic tradition. Moreover, the plurality in Fiqh has progressed largely compared to certain eras in history, for example, four Imams of different school of thought leading separately in one Masjid. The solution to this is simple, the laymen doesn’t have a school of thought rather he follows his local scholar (which is generally accepted throughout tradition). However, this does not mean the scholar should feel he is infallible nor does this allow monopolisation of knowledge as indicated earlier. This is in fact another cause to the problem of sectarianism. Rather the masses should be endorsed different layers and various levels of Islamic knowledge and not be attacked with the ‘all or nothing’ mentality. It is key for everybody to be a knowledgeable consumer. This entails that if you do not have basic knowledge, you will be spoonfed, taken on a ride and taken advantage of (similar to that of information bias).
Finally, I would like to highlight on spreading the good teachings of Islam as mentioned earlier. Many have a tendency to publicly critique people of groups or request scholars or institutions to critique. In simple words, take sides and hold the banner of a certain sect. In response to this, we need to take into consideration an example from Islamic history. Before the Qur’an was even compiled in a book format the ‘Qur’an’ of Musaylamah’ was published to the people. Despite being aware of this, not a single companion consumed time in refuting it. This is done in the faith that Allah will always preserve the truth and will never let falsehood prevail. Deviance and falsehood is infinite, so a student of knowledge needs to be productive and have an unprejudiced study of the Qur’an with its application and the Sunnah along with the understanding of Seerah (biography of the Prophet - PBUH). A key principle in approaching text is open mindedness with a balanced mentorship.