Grace Community Church on Roscoe Boulevard held services that did not require visitors to wear a mask.
Those who left the service Sunday evening say the church is a vital service.
"It is our right to express our religious freedom," parishioner Erik Miramontes says.
RELATED: Newbury Park church holds indoor services despite judge's orders, drawing counter-protesters
Grace Community Church was not the only congregation gathering inside despite the public health measures restricting such gatherings.
In Newbury Park in Ventura County on Sunday, tempers flared outside Godspeak Calvary Chapel after the church defied a judge's temporary restraining order banning sermons inside.
The county had sued the church for violating public health orders.
Back in Sun Valley, the church is looking into taking legal action after the city issued a cease-and-desist order threatening Pastor John MacArthur with a daily $1,000 fine and possible arrest.
He says complying with the state's order would be disobeying his faith. MacArthur also says the government has no right to dictate how or where they hold their Sunday services.
A tent for outdoor viewing has also been set up there.
Correction: An earlier version of this story stated that the Sun Valley church is taking legal action, but it should have stated that the church is looking into taking legal action.
RELATED: Los Angeles County warns places of worship to hold services outdoors
Editor's note: An earlier version of this story stated images showed hundreds attending service at Grace Community Church on Sunday without masks. It is not clear when those images were taken and ABC7 is still in the process of trying to verify them.