Day of the Immaculate Conception of the Virgin Mary, whose cult is very popular in Catholicism — one of the major festivals dedicated to the Mother of God. In the ancient tradition of the Church was not the version of the sinless conception of Mary by her mother Anna. Version of the Immaculate Conception was formalized dogma of Pope Pius IX December 8 in 1854, although in 1476 the triumph of the Immaculate Conception (December 8) introduced the Pope Sixtus IV.
According to Catholic doctrine, Mary, the only people from the moment of conception was freed from original sin and, at the same time, be protected from the very possibility of sinning.
Orthodox Church, as a Catholic, also teaches that Mary did not commit any sin in your life. But the reason that she sees in the presence of Maria's moral integrity, intelligence and willpower. The Catholic Church teaches that the ability not to sin has been there at conception.
In the churches of that day a solemn service.