Thats quite Christian. This is catholic;
all creatures who serve God ought also to serve Mary; for all angels and men, and all things that are in heaven and on earth being subject to the dominion of God, are also subject to the dominion of the gloious Virgin.
Ligouri; The Glories of Mary pp 26
it must also be true that only through Mary can we hope for and obtain this great gift of perseverance. And we certainly shall obtain it, if, with confidence, we always ask it of Mary. She herself promises this grace to all those who serve her faitlifully in this life.|
Ligouri; The Glories of Mary pp 90
because the Virgin does not save all sinners, but only those who serve and honor her.
Ligouri; The Glories of Mary pp 232
Thats a fraction of what i could post. Catholics do not, by their own words and actions serve only God. Which by definition makes the rcc outside of the one true church.