That early Christians continued to recognize Mary as the one who gave birth to Jesus is evidenced in a variety of early Christian texts and artifacts. One example is the ΧΜΓ symbol, probably signifying Χ(ριστὸς ὁ ἐκ) Μ(αρίας) Γ(εννηθείς) (“Christ, the one born of Mary”).
But why? Well… it proposes this as connected to the oldest version of the Gospel of Matthew.
So… if he is correct… then Jesus and the Gospel are connected to Mary… and Mary to the gospel story.
Holy Protestant Heresy, Pope Peter!