Protestants believe that they are part of the Church by faith in Jesus Christ according to the Word of God, the Bible. They and all who believe in Jesus are part of His body. The Church is NOT an organisation or earthly institution but the spiritual house and temple of God as per the Apostle Peter in his First Epistle and the Apostle Paul in the First Epistle to the Corinthians.
The organised, institutionalised “Church” is an apostate, idolatrous religion.
Clement’s first Epistle to the Corinthians (yes I have a copy) is not a proof of Roman pre-eminence. Any student of Church history would know that at this early date the Bishop of Rome was not recognised as having authority over the whole Church Catholic. The letter rebukes the congregation for deposing their elders. He also refers to the Churches of Smyrna and Ephesus on an equal level with Rome.
Ignatius of Antioch rebuked and encouraged Rome in his letter. It was a Christian communal, filial duty of fellowship to admonish one another. There is no indication of a Papacy, so I wouldn’t wax too lyrical about the propaganda you have been reading.
Irenaeus, in Against Heresies, confronts gnostics who tout a secret oral doctrine they obtained from the Apostles (hmmm, ring any bells?) and shows that it is the Church of Christ that can trace their authority to the Apostles by the scriptures and their faith.
I am a Protestant. I believe that the early Church was Catholic in that it was a common, universal body of believers through faith in Christ. Please note that this Church of the early fathers was not supervised by Rome or by a Pope so the claim by the RCC that they gave us the Bible and they were the Church is false. It was the Apostolic Church of Christ. In fact the Byzantine Church did more to give us the Bible and have a greater claim to Apostolic provenance than Rome ever has.
After the Constantinian change the church was infused with paganism and idolatry. The Donatists realised thay could not be part of a State Church with a Pontifex Maximus and left. They have my heartfelt sympathies.The truth is that Jesus Christ is the Head of the Church and nobody else.
There have always been believers in Christ and the word of God, the Bible. They were persecuted as heretics by the “Church”. The Waldenses and Albigenses were crushed by a Crusade in the early 1200s by the Latin Church. In England in the late 1300s and up until the early 1500s the Wycliffites evangelised England. Jan Hus (1415) and his followers were hounded and murdered by Rome for expressing faith in Christ contrary to the established “Church”.
In 1517, God used Martin Luther, a priest and monk to awaken Europe to the truth of God’s word. In fact most Protestants were priests who realised that the Papacy were misleading the laity and increasingly becoming Apostate. John Calvin in France and Knox in Scotland were also persuaded of the truth of Justification by faith in Jesus Christ and His atoning work on the cross. They may not all see eye to eye on minor points of scripture but are persuaded of the weightier matters pertaining to salvation. We are justified by God through faith in His blood. Hallelujah, Amen!
So, what can be said of a visible Church full of ritual and idolatry and without the Word of God? Which is the true Church, those justified by faith in Jesus or those who persecute His followers? Who is more Orthodox, those that maintain the orthodox doctrines of scripture or those who add to scripture with Papal bulls and decrees, councils and blasphemous pronouncements?
The Lord Jesus Christ taught that the Kingdom of God is within you and doesn’t come with observation. He taught faith in Him as a requirement for salvation.