In a six-paragraph statement, local leaders of the Episcopal Church, United Methodist Church, Evangelical Lutheran Church in America, Presbyterian Church (USA) and the United Church of Christ faiths voiced their opposition to the proposal, which would define marriage as only that joining a man and a woman.
The fiercely debated ballot initiative has been backed by Roman Catholics, Southern Baptists, the Church of Jesus Christ of Latter Day Saints (Mormons) and some Muslim officials in California.
Set for a March 7 vote, Proposition 22--also called the "Knight Initiative," after its author, state Sen. Pete Knight, R-Palmdale--is just 14 words long: "Only marriage between a man and a woman is valid or recognized in California."
Supporters say the initiative upholding current law is necessary in the face of a recent Vermont Supreme Court decision paving the way for possible gay marriages in the state. Federal law requires all states to recognize marriages performed in other states.
Speaking at the Episcopal Cathedral Center of St. Paul in Los Angeles, the mainline church leaders also detailed their support for both gay civil rights and possible homosexual marriages--even though all of their denominations are divided on the volatile issue of the role of gays in religious and secular life.
"From a more positive perspective, one may find reasons to be supportive of the prospective benefits and protections of contracts of marriage or the equivalent of marriage between couples of the same gender, if and when this becomes a possibility," the statement said.
"While we do not speak officially for our denominations, we do believe we speak for many others in making this recommendation" that the ballot initiative be defeated.
Bishop Roy Sano of the United Methodist Church's California-Pacific Conference said anti-gay marriage activists must not foster "a state that approaches hysteria and hatred" over the divisive issue.