While the developed doctrine of the Trinity is not explicit in the books that constitute the New Testament, the New Testament possesses a "triadic" understanding of God and contains a number of Trinitarian formulas. The doctrine of the Trinity was first formulated among the early Christians and fathers of the Church as early Christians attempted to understand the relationship between Jesus and God in their scriptural documents and prior traditions.The Comma Johanneum in 1 John 5:7, is a disputed text which states: "There are three that testify in heaven, the Father, the Word, and the Holy Spirit, and these three are one." However, this passage is not considered to be part of the genuine text,[a] and most scholars agree that the phrase was a gloss.
There have been images of Madonna and child; Mary seated in a chair with the child on her lap. Some of these images look very similar to images that we know about from some of the pagan goddesses at the time.Isis and Horus, from a statue in the Berlin Museum © Madonna Enthroned by Fra Filippo Lippi, mid 1400s ©
Isis, for example, was seated in such a chair with the infant Horus on her lap in the same way.
When Christianity was spreading across the Empire, it's clear that it deliberately took images from the pagan world in which it lived and into which it spread and used those images. Old holy wells and shrines were turned into Christian shrines. In Egypt a shrine of Isis was deliberately and self-consciously re-created as a shrine of Mary.
The survival of ancient communities was intimately dependent upon the fertility of the land, so their religious symbolism and festivals reflected this fundamental bond between humans and the cycles of nature. A number of Catholic holidays and myths parallel the timeline and adopt the symbols of pre-Christian fertility festivals. In Catholicism, Jesus Christ is thought to have been born on December 25, Christmas Day. In pre-Christian Roman religions, the Winter Solstice was a core sacred event that took place on December 25 at the time of the Julian calendar. The best known custom was the Roman festival of Saturnalia, which was celebrated similar to Christmas with drinking, fires, gift-giving, and tree worship.
The cross is actually an ancient pagan symbol
that only later began its association with Christianity some 300 years
after Jesus' time during the reign of the pagan Emperor Constantine. The
cross symbol was used long before the Christian era, one form of which
goes back at least to the ancient Egyptian ankh.
The naming of the celebration as “Easter” seems to go back to the name of a pre-Christian goddess in England, Eostre, who was celebrated at beginning of spring. The only reference to this goddess comes from the writings of the Venerable Bede, a British monk who lived in the late seventh and early eighth century.
All so called "christian" practices and doctrines promoted by the catholic church primarily are of roman and other pagan origins. Papacy was nothing but a continuation of the roman empire. The roman empire could not stop the spread of the true christianity and they adopted it in a form that suited them. Probably most people know these facts in the internet era.