Portugal is a country with very deep Catholic roots, largely marked by the history of the Second Crusade and the reconquest of the Iberian Peninsula from the Muslim Moors. The first Portuguese monarchs in the 12th and 13th centuries were Christian knights strongly linked to the efforts to Christianize Europe promoted by Bernard of Clairvaux, among others. These roots would totally condition the history of Portugal and the way in which religion has been understood, taught and transmitted over the centuries. Portugal is inseparable from the history of the Catholic Church and incomprehensible without it. 

This means that over time the relations between political power and religious power were almost like two sides of the same coin. Medieval monarchs were theoretically subordinated to religious power, which gave them an almost metaphysical mission, legitimacy and dignity. This does not mean, in practice, that there were no internal tensions. They were substantive and were often associated with the authority to appoint bishops and consecrate chapels and churches. Likewise, monarchs sought to limit the Pope's supreme power and withdraw from his jurisdiction whenever they deemed it convenient for their interests. Even so, it was common for monarchs to donate large properties to the Church and to the religious orders that were taking root in the Kingdom of Portugal. The result was the accumulation of ecclesiastical heritage over the centuries, a fact that would cause distortions and conflicts at the economic and social levels. But the inseparable relationship between political power and religious power remained and was strengthened when, in 1494, the Treaty of Tordesillas was signed between Portugal and Spain, concretizing and adjusting the division of lands and seas made by the papal bulls Inter Caetera, of the Pope Alexander VI, Borgia. Thus, the foundations of the missionary mandate were laid, which would guide Portuguese navigators in the discovery and colonization of new lands in America, Africa and Asia. 

The greed for ecclesiastical property and for the primacy of political power over religious power in the colonies created more tensions between political and religious power in the 17th and 18th centuries, with strong attacks on religious orders and growing uneasiness and impatience on the part of influential sectors of the rising bourgeoisie. In 1820, under the influence of the French Revolution, a liberal revolution took place in Portugal, taking advantage of the royal court's flight to Brazil following the Napoleonic invasions

In the 19th century, the Catholic religion continued to be the official religion of the State, although with new attacks on religious orders and confiscation of their property and some gains for freedom of conscience and expression and for the private religious freedom of foreigners. In 1910, the republic was proclaimed and religious freedom and the separation of Church and State were decreed, in the midst of new nationalizations of ecclesiastical property. The relations between the Church and the State assumed new points of tension that the Concordat of 1940 tries to attenuate. The freedom of religious confessions made small advances with the 1933 Constitution of the Estado Novo and, later, with the Religious Freedom Law of 1971. But it was after the Carnation Revolution of April 25, 1974, and especially with the promulgation of the 1976 Constitution, that religious freedom and the separation of religious communities from the State were definitively assured. The culmination of this long and tumultuous process is represented by the Religious Freedom Act of 2001 and the Concordat of 2004. Since then, religious freedom, of the majority and minorities, has known broad and effective protection unprecedented in the country's history.

This aspect must be underlined, due to its importance. There have always been religious minorities in Portugal, such as Jews and Muslims. Over the centuries, due to the circulation of ideas and people, minorities of Protestants, Evangelicals, Adventists, Jehovah's Witnesses or Mormons emerged; it is impossible to mention them all. In the past, when they were not openly persecuted, they could be legally and socially discriminated against. The 2001 Religious Freedom Act radically changed the situation, creating a climate of equal religious freedom and even interreligious solidarity. This is visible, for example, when different religious communities take joint positions on divisive issues such as abortion or euthanasia. The latest census of 2021 shows that Catholics are 80.2% of the population, Orthodox 0.88%, Muslims 0.4%, and Jews 0.033%. On the other hand, in the last 10 years, Evangelicals went from 0.84% to 2.1% of the population, the highest increase ever recorded. The same allows us to conclude that the 2001 law has allowed a true competition of religious ideas, although still bearing only slow and marginal effects.                                                                           Jonatas Machado