Do you think that these many groups considered themselves orthodox
What does that have to do with anything? Why would it matter what heretics think of themselves? The early church elders contended for the faith just as Christians do today. These were men personally trained by the apostles.
We see a perfect unification in Christology from the outset, to the many examples that predate Constatine considered in this thread, as well as professions of faith by Christians on the board.
Because of their vast written record, we know when the heresy arose, and who did it. They name names.
For example, several of the early church leaders mention the Nicolaitans in their writings. Isidore of Seville, Irenaeus, Hippolytus, Epiphanius, and Theodoret, linked this group to Deacon Nicolas (Acts 6:5), holding that he was the author of the sect and the heresy thereof.
- Isidore of Seville wrote, “The Nicolaites (Nicolaitans) are so called from Nicolas, deacon of the church of Jerusalem, who, along with Stephen and the others, was ordained by Peter.
- Irenaeus added, “They (Nicolaitans) lead lives of unrestrained indulgence … teaching it is a matter of indifference to practice adultery, and to eat things sacrificed to idols.”
- Victorinus of Pettau held that the error of the Nicolaitans was that they ate things offered to idols.
At the time the Book of Revelation was being written, the Nicolaitans were a formidable force bent on teaching false doctrines in the church and their deeds and doctrines were widespread, leading many astray into apostasy. They were a real problem to the point that they drew the attention of Heaven. In a letter Jesus personally dictated to John to be sent to the church at Pergamos, Jesus rebuked the church for the fault that there were some Christians there who had embraced the false doctrines of the Nicholaitans. In these words Jesus rebuked them,
14 But I have a few things against thee, … 15 So hast thou also them that hold the doctrine of the Nicolaitans, which thing I hate. (Re 2:14, Re 2:15)
Confronting heretics and rebuking them is a honored tradiion in Christianity because heretics will always be with us until Christ returns.
Here's a couple examples that are more in line with the topic of this thread.
Polycarp (AD 69-155) was the bishop at the church in Smyrna. Irenaeus tells us Polycarp was a disciple of John the Apostle. In his Letter to the Philippians he says,
Now may the God and Father of our Lord Jesus Christ, and the eternal high priest himself, the Son of God Jesus Christ, build you up in faith and truth...and to us with you, and to all those under heaven who will yet believe in our Lord and God Jesus Christ and in his Father who raised him from the dead.
Ignatius (AD 50-117) was the bishop at the church in Antioch and also a disciple of John the Apostle. He wrote a series of letters to various churches on his way to Rome, where he was to be martyred. He writes,
Ignatius, who is also Theophorus, unto her which hath been blessed in greatness through the plentitude of God the Father; which hath been foreordained before the ages to be for ever unto abiding and unchangeable glory, united and elect in a true passion, by the will of the Father and of Jesus Christ our God; even unto the church which is in Ephesus [of Asia], worthy of all felicitation: abundant greeting in Christ Jesus and in blameless joy.
Being as you are imitators of God, once you took on new life through the blood of God you completed perfectly the task so natural to you.
There is only one physician, who is both flesh and spirit, born and unborn, God in man, true life in death, both from Mary and from God, first subject to suffering and then beyond it, Jesus Christ our Lord.
