Two main world’s religions, Christianity and Islam, are not unified religious movements. Both of them consist of several approaches and insider movements as a result of historical separation and division. When the religions emerged, there was no over-all authority apart from the Spirit of God. The Jerusalem Christians assumed leadership, and the Apostles, but they sometimes were at cross purposes with each other. Through the years, and especially as teachings fundamentally contrary to the Gospel crept into Christian circles, Christians tried to establish a unity in order to meet such challenges. The first example of this was the development of the Catholic Church (as distinct from the Roman Catholic Church with its characteristic practices) in the third and fourth centuries. Still, the basis of this unity is the canon of the New Testament. Similar to Christianity, the symbol of unity in Islam is Qur’an (Smith 2002).
The min denomination in Islam are Sunni, Shi’a, Sufism, Kharijite, Ibadism. And here again there was no over-all unity. That is, the division began in isolated local movements, and it was never integrated by a single organization or program. Only recently have efforts to relate the separate movements found practical expression in the ecumenical (meaning "the whole inhabited world") movement which includes most bodies. Three different emphases are made: some stress the institution, others correct belief, and still others some manifestation of God. Any one group will maintain evidence of all three, but the major emphasis will be on one. In contrast to Christian world, political decentralization of Islamic world reflects religious decentralization and division. The majority of countries are organized on the basis of religious values and traditions. For instance, Oman is the main country inhabited by Ibadi; Sunni states are Saudi Arabia, Turkey, Iraq; Shi’a live mainly in Iran. Religious separation lefts no real basis for conducting the practical affairs of church life other than voluntary cooperation as far as people are willing to give it. Some basis of outward union had to be established, and the tendency of churches of this type has been to identify true faith which alone brings the Church into existence with acceptance of a particular doctrinal standard.