The Athanasian Creed says:
“Now this is the catholic faith: We worship one God in trinity and the Trinity in unity, neither confusing the persons nor dividing the divine being. . . .
“What the Father is, the Son is, and so is the Holy Spirit. . . .
“For this is the true faith that we believe and confess: That our Lord Jesus Christ, God”s Son, is both God and man.
“He is God, begotten before all worlds from the being of the Father, and he is man, born in the world from the being of his mother — existing fully as God, and fully as man with a rational soul and a human body; equal to the Father in divinity, subordinate to the Father in humanity. . . .
“Although he is God and man, he is not divided, but is one Christ.
“He is united because God has taken humanity into himself; he does not transform deity into humanity.
“He is completely one in the unity of his person, without confusing his natures.
“For as the rational soul and body are one person, so the one Christ is God and man.
“The ”Athanasian” Creed boldly uses the key Nicene term homoousios (”one substance”, ”one in Being”) not only with respect to the relation of the Son to the Father according to his divine nature, but that the Son is homoousios with his mother Mary, according to his human nature.
It might be foolish to even try to apply logic to this alphabet soup of self-contradiction but if Christ is one in being with God and Mary is one in being with Christ, then is not Mary one in being with God. Doesn’t this mean there ought to be a quaternity rather than a trinity?