In the 14th century, when it was united with Poland, Lithuania became a Christian country. It was the last nation in Europe to accept Christianity. Today, about three-quarters of Lithuanians are Roman Catholic. About 5% of the population is Russian Orthodox and there are also small communities of Protestant Uniates (a sect that unites elements of Catholic and Orthodox beliefs) and Old Believers (an Orthodox sect that rejected certain reforms to the Orthodox Church).

 During the Soviet era, the Catholic Church was suppressed and many Lithuanian Catholic priests were deported to Siberia. Churches were converted to warehouses and monasteries were closed. Nevertheless, many Lithuanians privately maintained their faith and the church became associated with the nationalist cause. After independence, churches were reopened and many Lithuanians received adult baptism or reconfirmed their marriage vows in a church.

The Hill of Crosses, located in the north-central part of the country near the town of Šauliai, is one of the most significant religious and national sites in Lithuania. The hill is entirely covered with wooden and iron crosses of all sizes. It is thought that the first crosses were set on the summit of the hill to honour those who revolted against the czarist regime in the 1830s and that more were added after the rebellion of the 1860s. In the 1950s, Lithuanians erected crosses in memory of those who had died in exile in Siberia under the Soviet regime. The Soviets bulldozed the hill in the 1960s and destroyed the crosses, but the Lithuanians continued to erect new crosses. Since independence, thousands of crosses have been added by Lithuanians from throughout the world. Pope John Paul II contributed a cross during his visit in 1993.

 Before the country's official acceptance of Christianity in 1387, Lithuanians practised a form of nature worship. They believed all natural things, including trees, streams and rocks, possessed a spirit, and they worshipped phenomena such as thunder, rain and storms. Religious rituals were held outdoors, usually in a sacred grove of trees or by the waters of a holy stream. People also believed strongly in an afterlife. The dead were buried with the household objects, food and drink that they would need in the afterlife. Warriors and leaders were sometimes buried with their horses. Today, a few Lithuanians keep these ancient beliefs alive.
  Did you know?
Before the Second World War, Vilnius had a large Jewish population and was known as "the Jerusalem of Lithuania." The Jews accounted for more than one-third of the city's population. The city was a centre of Jewish culture and had 96 synagogues. All but one were razed by the German and Russian armies during the war. Today, about 0.3% of the population is Jewish.

  Did you know?
The Church of St. Teresa is a pilgrimage site in Vilnius. The Church's Gates of Dawn chapel contains an image of the Madonna of Mercy that is said to have miraculous powers. Pilgrims climb the steps to the church on their knees.