The answer
When Catholic missionaries came to Egypt with the claim to preach Christianity to non-Christians, they managed to convince some of the Coptic Orthodox Christians to leave their church and become Catholics. They approached them with the false pretence that they did not need to change anything in their faith or church rituals except that they will be under the papacy of the Pope of Rome instead of our Pope of Alexandria.The Coptic Catholic Divine liturgy is very similar to the Coptic Orthodox except for the Creed ; as the Catholic creed is recited instead. In addition, being Catholic, the Coptic Catholic Church has adopted all the new dogmas of the Catholic Church. For example, the Immaculate Conception, the purgatory, the procession of the Holy Spirit from the Father and the Son etc.
Answered by His Eminence Metropolitan Youssef (opens in a new tab)