Social and moral issues such as abortion have since been brought to the center of the national agenda. Some argue that this new emphasis is impeding political and economic reforms needed to restore robust growth to the world's seventh-largest economy.
Brazil remains the world's largest Catholic nation. Pope Francis is expected to travel to Rio de Janeiro next month on his first trip abroad as pontiff, in part to try to reverse the exodus away from Catholicism.
Evangelical churches with their vibrant preaching, emotional prayer and singing, seem to appeal to Brazilians more than the liturgical masses of the Catholic Church. They also use electronic and social media more effectively to proselytize.
Many Brazilians who join evangelical congregations say that fundamentalism has brought meaning to their lives, and that they no longer identified with the Catholic Church.
So pervasive is this new faith, one in four Brazilians is an evangelical Christian today and their churches have multiplied and become wealthy institutions that own radio and television networks, finance political campaigns and even fund their own political parties.
Catholic priests are banned from running for public office. Evangelical churches, on the other hand, actively encourage their pastors to engage in politics and often use the pulpit to persuade their followers who they should vote for.
"Today there are 44 million mainly Pentecostal evangelicals in Brazil, which is a large social force. Obviously, this was going to change things in Congress," Fernando Altemeyer, a former Catholic priest who teaches theology at the Catholic University of Sao Paulo says.
The evangelical presence in the Brazilian Congress has been very much in the public spotlight. Pastor Marcos Feliciano, of the Social Christian Party was named chairman of the chamber's Human Rights and Minorities Committee.
Feliciano once stated that John Lennon's murder was divine retribution for saying the Beatles were more famous than Jesus Christ.
The committee's sessions have been disrupted almost daily by demonstrators demanding Feliciano's ouster. He has ordered guards to remove the protesters and closed the committee to the public.