The rally was a show of support for lawmakers who oppose abortion and same-sex marriage and a message to other politicians that they should not ignore Brazil's fast-growing evangelical churches if they want to stay in office.

"Gay activism is moral garbage," Malafaia roared into the microphone to a cheering crowd on the grassy esplanade of the Brazilian capital. "Satan will not destroy our family values."

The rise of evangelical Christians as a conservative political force in Latin America's largest nation has put the ruling Workers' Party on guard and led President Dilma Rousseff - who is seeking re-election in 2014 - to appoint an evangelical bishop to her cabinet.

The growing clout of evangelical churches is also bringing social and moral issues such as abortion to the center of the national agenda, some say at the expense of political and economic reforms needed to restore robust growth to the world's seventh-largest economy.