With his decision to legalize same-sex marriage, Catholic Supreme Court Justice Anthony Kennedy betrayed Christ similarly to Judas, a Catholic activist said Wednesday.

"Judas betrayed Jesus with a kiss. Anthony Kennedy betrayed him with a vote," Hugh Brown of the American Life League said at a press conference on the Supreme Court's decision last Friday to legalize same-sex marriage nationwide.

And he should be ex-communicated from the church for his ruling, said Michael Hichborn of the pro-Catholic Lepanto Institute.

But Kennedy, who wrote the majority opinion, didn't just betray Catholicism with his ruling in Obergefell v. Hodges, both Hichborn and Brown said. Kennedy and the four justices who joined him pose a serious threat to religious liberty in the United States, the two said with other speakers at Wednesday's press conference.

Standing in front of the Supreme Court, Hichborn said the court's decision "has declared war against every Christian in America."

In a statement read aloud, Rev. Shenen Boquet of the Catholic Human Life International, said the court's decision has set the stage for a "cold civil war" among families, communities and churches.

Wednesday's speakers, who represented nine Christian groups, said they fear that the court's decision to legalize gay marriage will bring a myriad of lawsuits against Christian business owners and Christian employees who disagree with gay marriage.

Hichborn said he expects "an explosion of such cases," predicting that gays and lesbians will ask Christian or Catholic churches to perform their weddings.

Bob Laid of the Cardinal Newman Society, a Catholic education advocacy group, said he fears Catholic schools across the country will be forced to adopt employment provisions and benefits that extend to married same-sex couples.

Scott Schittl of CitizenGo, an international religious liberty group, said he expects Christian bakers and florists in the U.S. will be forced to participate in gay marriages even if it goes against their conscience and religious beliefs.

John-Henry Westen, editor of the conservative news organization LifeSiteNews, said legal action in other countries could foreshadow impending assaults on religious liberty in the U.S.

"In Ireland, churches face fines for not letting same-sex couples have ceremonies on church property," he said. "In France, negative speech against homosexuality is banned, and in the Canadian province of Quebec, parents are forced to teach their home-schooled children the government's sexual ideology."