This I write in response to DavidW's assertion here.
All I want to say here is that it makes a difference at what point in history certain things are discussed. Context, you know? If there wasn't a great deal of discussion about a certain topic beforehand or contemporarily for a given writer and he makes some comments that, if placed in someone's mouth today, AND if that person today had been educated from the Scripture and refuted from the Scripture and then refused correction, then the label "heretic" would certainly apply. So it has to do with what people had a responsibility and opportunity to know, and in what capacity. "From the one to whom much is given, much will be demanded" - Luke 12:48. It also has a lot to do with resistance to correction.
For example, I can share the Gospel with some total unbeliever, let's say a Muslim. He hears the Gospel, is pricked to the heart, is regenerated by the Holy Spirit, repents of his sin and places his full faith and trust in Christ. We then start walking to a place so I can teach him about the Bible a bit and set up times to meet later so I can disciple him, "teaching him to observe all that I commanded you" (Matt 28:20). On the way, I get run over by a truck. Said just-converted man knows the name of Jesus, that He is the Savior, that He was crucified for our sins and raised to bring us eternal life, that he himself is a sinner and needs to have a growing friendship with the Savior...and that's it. And it just so happens he doesn't meet another Christian for quite some time, during which time he reads the Bible and reaches the correct conclusion, say, that "My sheep hear My voice, and I know them, and they follow Me; and I give eternal life to them, and they will never perish; and no one will snatch them out of My hand" (John 10:27-28) and thus that he will never perish, which is a great encouragement to him. He also forms the erroneous position that God is a unitary being with three various modes of self-expression. Then he meets another Christian, finally, who knows the Bible better than he. Shall that Christian, upon learning that this man holds to modalism and learning of his story of faith, then harshly rebuke the younger believer for his heresy? No! He'd teach him the true Scriptural position of the Trinity. A mark (not a cause, but an effect) of a regenerate heart is a proper response to biblical correction. This guy, being for the sake of argument (from our "omniscient view" as the narrators of the story) a true regenerate adopted child of God, not self-deceived or playacting, would inevitably submit himself to correction. In the real world, you never know for sure what's in someone else's heart, so you have to watch for the fruit. Stubborn resistance to biblical correction on essential doctrine is a great sign of an unregenerate heart, but auto-downloads of the entire corpus of knowledge in the Scripture into the brain is not to be expected. So the amount of knowledge beyond a bare minimum is not a sign of that; refusing biblical correction is.
So, having said all that, I am not going to put these early church writers in the position of forcing their words into commenting on issues they didn't know much about nor had experienced much discussion of. Just as much of the formal and conciliar formulations of Christian doctrine were hammered out in response to the rise of large movements of support for doctrines that, it would turn out, were incorrect and of central importance to the Gospel and the nature and identity of God Himself, just as Roman anathemas "don't work retroactively", I don't expect these early church writers to have the opportunity of exposure to the breadth and depth of theology and reflection on every single issue that I have opportunity of exposure to. I have every reason to expect that these men, being adherents to the idea that God-inspired Scripture was to be held to on a higher level of authority than non-Scripture, would hold to MY positions, were they alive today. Hope that helps clear this up. It will thus be dishonest of you to continue saying things like "You don't see the problem with stating that the early Christians, many of whom sat at the feet of Apostles and listened to them speak, who gave us the New Testament we know today and without whom Christianity would have ceased to exist, were all heretics?"
So I hope you will stop.