Those who knew Nestorianism was heresy, simply knew it was so because of the Holy Spirit who helped interpreted the scriptures.
The only way we can rightfully divine the word of truth is to ask God to help us interpret it correctly. All Christians should understand that those who stumble into heresy (and we all do to various degrees) is because we fail to listen to the spiritual truths taught by the Holy Spirit.
once again, it’s all your personal opinions. Why should anyone trust you over the millions of other so-called “christians”?
And of course you can document this by quoting from the Council of Ephesus.
And how do you know you are listening to the Holy Spirit and not Satan?
The Church of the apostles was definitely one: "There is one body and one spirit," Paul wrote, "just as you were called to the one hope that belongs to your call, one Lord, one faith, one baptism, one God and Father of us all" (Eph. 4:4-5). Paul linked this unity to the Church's common Eucharistic bread: "Because there is one bread, we who are many are one body, for we all partake of one bread" (1 Cor. 10:17). Jesus had promised at the outset that "there would be one flock, one shepherd" (John 10:16).
So which one church is the Church that Christ promised And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. Mat 6:18
If there isn't one church, Christ is a liar.
A few questions:
1. Where did Jesus give instructions that the Christian faith should be based exclusively on a book?
2. Other than the specific command to John to write the Revelation, where did Jesus tell His apostles to write anything down and compile it into an authoritative book?
3. Where in the New Testament do the apostles tell future generations that the Christian faith will be based solely on a book?
4. Where did the table of contents of the Bible come from?