The California Supreme Court last week temporarily halted gays and lesbians from obtaining marriage licenses at San Francisco City Hall pending a full hearing in May or early June. Scratch the surface of the forces fighting same-sex weddings in San Francisco, one can find that most conservative Christian activists oppose same-sex marriages.

The nation's three largest Christian denominations -- the 66-million- member Roman Catholic Church, 16-million-member Southern Baptist Convention and the 8-million-member United Methodist Church -- all stand opposed to gays and lesbians being allowed to marry in Christian churches or in city hall. When it comes to same-sex marriage, most conservative Protestants, especially Southern Baptists and other evangelicals, agree with the Catholic bishops.

"It's a sin,'' said Arango, one of 600 members in a spirited Pittsburg congregation in Bay Area Pentecostal church, "We're not in favor of homosexual marriage. We condemn it. There hasn't been much discussion about this in church, because everyone already knows it's a sin."

"This is just one battlefield of a war,'' said Benjamin Bull, the church counsel of the Alliance Defense Fund. "This is a struggle between the Judeo- Christian view of marriage and a relatively small population group that is clamoring to redefine the majority's view of marriage.''

The United States Conference of Catholic Bishops this month reaffirmed its support for amending the U.S. Constitution to define marriage as "only the union of a man and a woman."

Miriam Guardado, a Catholic housewife in Oakland, agrees. "Homosexuals are free to live their lives, but marriage is not for them. Marriage is sacred," said Guardado, who has been married 25 years. "God formed man and woman, and we have to respect that. It's written in the Bible."

Most of the nation's larger mainline Protestant churches, despite their relatively liberal leanings, do not bless same-sex marriage. The bylaws of the United Methodist Church oppose same-sex marriage and describe gay sex as "incompatible with Christian teaching.''

The Gallup Pew poll, between 1996 and 2003, there was a 20-point drop in the opposition to same-sex marriages among white mainline Protestant Christians (from 64 percent to 44) and a 19-point drop among white Roman Catholics (from 60 percent to 41 percent) but only a 1-point decline among white evangelical Christians and African Americans.

For many Bay Area Christians, opposition to homosexual marriage flows from a mixture of faith, cultural and personal experience.