Mu‟tazila is one of the theologian schools of thought of the Muslims. They got originated in the eighth century Hijri when a student Wasil bin Ata made differences on some Islamic issues with his teacher Al-Hassan Al-Basri. The differentiating point between the two was; what will be the position of a person after committing a major sin? He/ She will be Muslim or not? Wasil bin Ata was of the view that such a person will be in an intermediate position neither (Neither Muslim nor non-Muslim) and he called him (Al Manzila Bayn Al-Manzilatain). This was a new idea and terminology presented by Wasil bin Ata for the first time. This article discusses the position of Mu‟tazilah as, their major doctrines and the differences with the basic Islamic believes and their effects on Muslim society. Also the paper will discuss the minor doctrines Mu‟tazilah such as rejecting of vision Allah in the day of resuscitation, creation of the Glorious Qur‟an, Good and Evil among others. Furthermore, the paper highlights on the unity of Muslims as a Unity of Muslims as a Prerequisite for Successful Islamic Civilisation, aims of unity in the Muslim Ummah, Reasons for this unity among the Muslims, and remedies on how to achieve unity in the Muslim Ummah.