The answer
The Church enjoyed unity in the first centuries, and Her patristic ethos was, “[O]ne heart and one soul” (Acts 4:32).
However, as time passed, divisions and schisms seeped in, and the heresiarchs were separated from the Church. In turn, they lost their membership in the Church, but the Church never lost Her unity.
Now, there are many faithful attempts, from a number of directions, to bring about the unity of the Church. They all revolve around the theme of “Ecumenical Unity.” These efforts have resulted in many positive advances, and their results will be revealed in the near future.
The vital issue that must be understood, however, is that the unity of the churches should be in Faith, doctrine, and teaching before it is realised externally. This is what is pleasing to the heart of Christ, to Him be glory, as He revealed it in His final prayer (John 17:11). We too desire this when we recite the Creed.
His Holiness Pope Tawadros II
Pope Tawadros II, My Faith: A Series of Dialogues on the Creed (Coptic Orthodox Patriarchate, 2014), 141–142.

