It was an unusual setting for a gathering of religious leaders.
About 20 Christians, Jews and Muslims came together at The Montrose Center, a counseling and community center for the LGBT community.
All of them condemned the mass shooting at the gay nightclub in Orlando this past weekend.
"We want the world to know that there is nothing Islamic about slaughtering innocent civilians in Orlando or anywhere else in the world," said MJ Khan, president of the Islamic Society of Greater Houston.
The gunman, American-born Omar Mateen, reportedly pledged allegiance to ISIS.
The speakers also pledged solidarity with the LGBT community and criticized those who discriminate against gays or Muslims.
Bishop James Dixon of The Community of Faith Church said he hopes the pain after the massacre will turn into passion.
"We must unite to denounce violence and hate crimes against all people anywhere under any circumstances," he said.
The Houston chapter of the Council on American-Islamic Relations plans to organize a blood drive for the victims of the shooting.
The gunman killed 49 and injured 53 others early Sunday morning.