In Spain, the three religions that were in almost constant conflict were:

Catholics. Protestants. Muslims

Explanation:  The major religion in Spain has been Catholic Christianity since the Reconquista, with a small minority of other Christian and non-Christian religions and high levels of secularization as of 2020. The Pew Research Center ranked Spain as the 16th out of 34 European countries in levels of religiosity, which is lower than Italy, Portugal and Poland, but much higher than the United Kingdom and the Nordic countries.[2] There is no official religion and religious freedom is protected: the Spanish Constitution of 1978 abolished Catholicism as the official state religion, while recognizing the role it plays in Spanish society

Protestantism in Spain has been boosted by immigration, but remains a small testimonial force among native Spaniards (1%). Spain has been seen as a graveyard for foreign missionaries (meaning lack of success) among Evangelical Protestants.[16] Protestant churches claim to have about 1,200,000 members.