Russian President Vladimir Putin has offered greetings to Orthodox Christians and all Russians on Christmas celebrated according to the Julian calendar on January 7.
A Kremlin press service statement quoted Putin as saying that Christmas "gives millions of believers joy and hope."
Putin said the holiday accustoms Orthodox Christians to "spiritual origins and fatherly traditions, and unites them around eternal Christian values" and the "centuries-old historic and cultural heritage of our people."
He also said that the Russian Orthodox Church and other Christian denominations have "made a significant contribution to strengthening high moral ideals in society, educating the growing generation, and solving vital social problems."
Putin attended Orthodox Christmas services at the Church of saints Simeon and Ann in St. Petersburg as the clock turned to January 7.
Meanwhile, Russian state television channels showed a live broadcast of the Christmas Eve midnight Mass from Moscow's Christ the Savior Cathedral.
Russian Orthodox Church Patriarch Kirill conducted the ceremonies at the Moscow site before hundreds of worshippers, including Prime Minister Dmitry Medvedev as well as several other Russian government and parliamentary officials.
Patriarch Kirill also sent greetings to the crew of the International Space Station (ISS) via a video linkup from the Christ the Savior Cathedral.
Addressing Russian cosmonauts Aleksandr Misurkin and Anton Shkaplerov, he said, "You are our heroes. You represent Russia up there, in orbit,” according to the TASS news agency.
The ISS crew also includes NASA astronauts Mark Vande Hei, Joe Acaba, and Scott Tingle, as well as Norishige Kanai of Japan.
Orthodox Christians in Russia and most other Orthodox countries celebrate Christmas according to the Julian calendar on January 7, two weeks after most Western Christian churches that use the Gregorian calendar.
January 7 is a national holiday in Russia, as well as in Belarus, Egypt, Ethiopia, Georgia, Kazakhstan, Macedonia, Moldova, Montenegro, Serbia, and Ukraine. The Armenian Orthodox Church celebrated on January 6.
In Bethlehem, Palestinians Christians -- angry with church land sales to Israelis -- scuffled with Palestinian police, as they attempted to block the arrival of the Holy Land's Greek Orthodox patriarch for Christmas celebrations.
Demonstrators banged on the sides of police escort vehicles, but Patriarch Theophilos III managed to safely move in his limousine to the Church of the Nativity for the traditional Orthodox Christmas eve observance.
In Istanbul, the Greek Orthodox Christian community celebrated Epiphany with the blessing of the waters.
Ecumenical Patriarch Bartholomew I, the spiritual leader of Orthodox Christians around the world and the archbishop of Constantinople, led the liturgy at the Patriarchal Church of St. George.
The Eastern Orthodox Church commemorates Jesus' baptism on Epiphany. Most Christian religions observe Epiphany to recall the three wise men who followed a star to find the baby Jesus.
In Egypt, President Abdel-Fattah al-Sisi attended an Orthodox Christmas service at a new church in a symbolic act of solidarity with his country's embattled Christian community, the Copts.
Sisi, a Muslim, told the packed cathedral outside of Cairo on the Orthodox Christmas Eve that "you are our family. We are one and no one can divide us."
His appearance at the cathedral along with Coptic Pope Tawadros II came as tens of thousands of soldiers and police were deployed outside churches in Egypt to secure against attacks by Islamic militants, who have targeted Christians for the past two years in bomb attacks that have killed about 100 people.