A day after conceding that gay marriage is inevitable, Focus on the Family CEO and President Jim Daly railed against the institution.

Daly, who took over leadership of the group after founder James Dobson stepped aside, told World Magazine this week that opponents of gay marriage have “probably lost.”

When asked how things stand on the issue, Daly replied: “We're losing on that one, especially among the 20- and 30-somethings: 65 to 70 percent of them favor same-sex marriage. I don't know if that's going to change with a little more age – demographers would say probably not. We've probably lost on that one.”

But in an op-ed titled Why the Same-Sex Marriage Experiment Will Not Work published by Fox News on Tuesday, Daly rails against the institution, warning that it will destroy religious liberty.

Heterosexual marriage, Daly writes, is “in the best interest of the common good.”

“However well-meaning the motivation, reengineering what God has designed is not only unwise, but radical and dangerous, too,” Daly says. “Here lies the last great frontier and the last gasp for those determined to re-engineer marriage. Those committed to this form of radicalism have systematically broken down the cultural barrier to same sex marriage by desensitizing people on the issue, stigmatizing those who oppose the movement and potentially criminalizing anyone who stands in opposition to them. The irony in our cultural discussion currently, is if you support traditional marriage, you are the one perceived by the cultural elite to be the radical.”

“If religious liberty is lost in America, we will cease to be the nation our Founders intended us to be. Our rights will no longer be derived from God but from man, and therefore, dangerously beholden to political despots,” he adds.