Creating unity is even more important now, with tensions heightened by the City Council's plan to train police for immigration enforcement and the nationwide fervor over immigration reform.
"In general, prejudice is based on ignorance, and if you get people to understand each other, that prejudice falls by the wayside," Rev. Enrique Sera, the church's leader, said.
Sera has tried his best to break down the barriers between the different segments of his own parish community, which includes about 2,500 registered families and others who attend the church but aren't registered. Latino families typically don't register, he said.
Before Sera came to St. Joachim in 2004, relations between the English- and Spanish-speaking congregants weren't as good.
"What everybody seems to mention is there was not much connection between the two sides," he said.
But the congregation has spoken multiple languages for at least 30 years, Sera said, and it is part of a diverse city.
"It reflects all the blessings and all the challenges of the city of Costa Mesa," he said.
In response, the church tailored its offerings to bring everyone into the fold.
A Mass in English and one in Spanish are held daily, with several in each language on Sundays. Sera wanted more opportunities to bring speakers of different languages together, so he incorporated both languages into major celebrations such as confirmations and Easter services.
"I don't really like for those great solemnities like that to have two different services," he said. "It should be one that everyone can come and feel like they're part of one family."