Brazil possesses a richly spiritual society formed from the meeting of the Roman Catholic Church with the religious traditions of African slaves and indigenous peoples. This confluence of faiths during the Portuguese colonization of Brazil led to the development of a diverse array of syncretistic practices within the overarching umbrella of Brazilian Roman Catholicism, characterized by traditional Portuguese festivities, and in some instances, Allan Kardec's Spiritism (most Brazilian Spiritists are also Christians). Religious pluralism increased during the 20th century, and a Protestant community has grown to include over 15% of the population. The most common Protestant denominations are Pentecostal, Evangelical, Baptist, Seventh-day Adventist, Lutheran and the reformed churches.
Roman Catholicism is the country's predominant faith. Brazil has the world's largest Catholic population. According to the 2000 Demographic Census (the PNAD survey does not inquire about religion), 73.57% of the population followed Roman Catholicism; 15.41% Protestantism; 1.33% Kardecist spiritism; 1.22% other Christian denominations; 0.31% Afro-Brazilian religions; 0.13% Buddhism; 0.05% Judaism; 0.02% Islam; 0.01% Amerindian religions; 0.59% other religions, undeclared or undetermined; while 7.35% have no religion.
However, in the last ten years Protestantism, particularly Pentecostal and/or Evangelical Protestantism, has spread in Brazil, while the proportion of Catholics has dropped significantly. After Protestantism, individuals professing no religion are also a significant group, exceeding 7% of the population in the 2000 census. The cities of Boa Vista, Salvador and Porto Velho have the greatest proportion of Irreligious residents in Brazil. Teresina, Fortaleza, and Florianópolis were the most Roman Catholic in the country. Greater Rio de Janeiro, not including the city proper, is the most Irreligious and least Roman Catholic Brazilian periphery, while Greater Porto