The answer
The Coptic Orthodox Church carries on with the same teachings, and faith that the original Church, of Peter, Paul, and the apostles taught two thousand years ago.One must first have an historical understanding of how the Church has progressed through those 2000 years of history, and how this history has been preserved in the Orthodox doctrines, practices, services, and even in the architecture itself.
In Orthodoxy, the basics of the Christian doctrine, worship, and government are never altered to meet the desires and temperament of the population, environment, or political climate. For example, one cannot claim to be Orthodox and reject the Divinity of the Lord Jesus Christ, His Holy Virgin Birth, Resurrection, and Ascension into Heaven and His Second Coming.
It is the One, Holy, Catholic, and Apostolic New Testament Church.
I would like to suggest that you visit your nearest Coptic Orthodox Church, and make an appointment to meet with its priests. They can answer many of your questions and offer you readings and documentation about the "first Christian Church" through the early Church Fathers.
For the fullness of the New Testament faith, I encourage you to become acquainted with Orthodox Christianity (which is different from Catholicism) on a more personal basis.
Answered by His Eminence Metropolitan Youssef (opens in a new tab)