No one is excluding anyone. The question is a red herring because it makes no sense. The creeds as we have them today did not exist at that time. It is like the old Saturday Night Live sketch, "What if Spartacus had a Piper Cub?"
However, since the creeds are built on the testimony of the apostles (the Bible) and the early church we have confidence that they are correct in all they teach.
What about those Protestants who claim to be "non-creedal"? Are they Christians according to your definition?
Any "protestant" who could not affirm the statements in the ancient creeds cited should have their Christianity questioned. There is much bad teaching among the "no creed but Christ" crowd, including poor constructs on the Trinity that lead to a form of modalism. The very purpose of the creeds is to sort out the bad theology among the faithful. And to help keep cults and heresies (wolves) away from the flock.
Saying something is "built on" the testimony of the Apostles is not the same as saying that it is what the Apostles themselves taught. It seems to me that the creeds add extra-Biblical concepts to the teachings of Jesus and the Apostles.
But I do not want to argue the point with you. I asked for the definition of Christian. Clearly, you think that the ecumenical creeds are important in part of any such definition.
Any "protestant" who could not affirm the statements in the ancient creeds cited should have their Christianity questioned. There is much bad teaching among the "no creed but Christ" crowd, including poor constructs on the Trinity that lead to a form of modalism. The very purpose of the creeds is to sort out the bad theology among the faithful. And to help keep cults and heresies (wolves) away from the flock.
I gather that you do not approve of the "non-creedal" churches. But are they Christians? If not, what would you call them?
One could also say "since the creeds add to the testimony of the Apostles"
>>>There is much bad teaching among the "no creed but Christ" crowd, including poor constructs on the Trinity that lead to a form of modalism. The very purpose of the creeds is to sort out the bad theology among the faithful. And to help keep cults and heresies (wolves) away from the flock.
Was Athanasius Christian? Was he a wolf among the flock? He was accused of believing in Modalism. In fact he was one of the main inital supporters of the Nicean version of the creed that eventually won out.
In rejecting Modalism (which incidentally, I agree is a false Doctrine) Another false Docrtine homouosis "of one substance" was substituted. That's what happens when decisions about what is orthodox or not is left up to men instead of the revelaed words of Jesus and his Apostles. They start arguing greek Philospohy instead of what Jesus and the Apostles actually said.
From the Greek ousia. The Nicene Creed uses the word homoousios, meaning "of the same substance or essence." The common notion of the Trinity as a single person who dons three different masks in order to relate to humanity is actually a heresy called modalism, which was condemned by Catholic councils. Beisner, God in Three Persons, 18.