Wait......you don't know that the Catholic Church admits it includes pagan practices? I and others have posted many times those admitions. I'll save you from having to look it up.
The missionary history of the [Catholic] Church clearly shows her adaptability to all races, all continents, all nations. In her liturgy and her art, in her tradition and the forming of her doctrine, naturally enough she includes Jewish elements, but also elements that are of pagan origin. In certain respects, she has copied her organization from that of the Roman Empire, has preserved and made fruitful the philosophical intuitions of Socrates, Plato and Aristotle, borrowed from both Barbarians and the Byzantine Roman Empire—but always remains herself, thoroughly digesting all elements drawn from external sources...In her laws, her ceremonies, her festivals and her devotions, she makes use of local customs after purifying them and "baptizing" them. [Twentieth Century Encyclopedia of Catholicism]
That's just one of many statements where they admit inclusion of paganism.