Both Roman Catholics and Orthodox view the other churches' traditions as invalid.

The Roman Catholic and Orthodox churches make the identical claim of apostolic succession, yet they are so different that they are not even in communion!

Roman Catholics and Eastern Greek Orthodox churches accuse the other of false doctrines both based upon tradition:

1. The Catholics reject several of the specific canons of the early ecumenical councils, but the orthodox accept them as inspired.

2. Catholics and Orthodox disagree on the dates of Christmas and Easter. While the Orthodox Church claims council at Nicea was inspired, yet is rejects the canons of Nicea on the date of Easter which the Catholics accept.

3. The Catholics teach purgatory, yet the Orthodox rejects it.

4. Orthodox rejects Papal infallibility, the decisions of the orthodox synods are considered infallible.

5. The Immaculate Conception is utterly rejected by the Orthodox.

6. Orthodox Church, priests can marry, but Catholics priests cannot.

7. The Roman Catholic Church introduced instrumental music no earlier than the 7th century and the Orthodox Church has never used instrumental music but like the apostles, sang without instrument.

8. In Catholic communion, the cup is withheld from the members, while the Orthodox floats the "crouton looking" bread cubes in the wine. Catholics believe the bread and wine (transubstantiation) become the literal body of Christ when the priest says, "this is my body". The Orthodox disagrees and says the change takes place at prayer. Catholics use unleavened bread, while Orthodox use leavened bread. Orthodox must keep a ridged schedule of fasts in order to have communion every week, but the most common practice is a minimum of four times a year during the four Orthodox Lents "Christmas, Easter, Peter and Paul, The virgin Mary. Catholics on the other hand, need not eat the hour before, to have communion every day. In the end, Orthodox offer communion weekly and Catholics daily. In practice most Orthodox laity have communion four times year and Catholics weekly.

9. For Catholics the "Transubstantiation" occurs when the priest says the words, "this is my body". For Orthodox the change occurs when the priest offers the prayer of thanks.

10. The "Filioque" scandal: Following the Nicene creed, the Orthodox Church believed the Holy Spirit proceeded from the Father alone. Then in 1054 AD the Roman church added to the wording of the Nicene Creed "And the Son" or the "Filioque." The Roman church believed the Holy Spirit proceeded from BOTH the Father and the Son.

11. Orthodox keeps the original Nicene Creed, accepted by the Universal Church, East and West, during the first millennium without the addition of "And the Son" or the "Filioque." It accepts, on faith, Christ's words in the Gospel, that the Father is the Unoriginate Source of the Life of the Trinity, with the Only-Begotten Son and the Holy Spirit Proceeding from the Father Alone.

Orthodox churches use the Julian rather than the Gregorian version of the Western calendar. As a result, they celebrate Christmas 13 days later than other Christian churches.

In Orthodox countries Christmas is on 7th of January and New Year is celebrated on 14th of January.