This whole thing so reminds me of the first and second century of Christian formation. The original followers of "The Way" did not have a creed of belief at first. A rich variety of theological views thrived (Gospel of Thomas, Epistle of Barnabas). Once a big geographical expansion occurs (After Pentechost) and the original apostles begin dying out, apostolic succession becomes very important (1st Clement; The Gospel of Mary Magdelene) and then those who take charge create creeds, not so much to proscribe outsiders, rather, to fence out fellow Christians who's views were different (Tertullian, Nicea, Chalcedon)
Oh, Chris, come on. We're talking about what the man himself said about his own art. There's no comparison with random documents written by unknowns over a century after Jesus' death.