The U.S. Supreme Court redefined the institution of marriage Friday to include same-sex couples, enshrining in law a monumental change that was unthinkable just a few decades ago.

The deeply divided court ruled 5-4 that same-sex couples have a constitutional right to marry, and that all 50 states must recognize the spousal rights of those who’ve already tied the knot.

A watershed moment in American culture, the decision signifies an even more radical change here in Georgia. The state was one of 14 that dug in their heels in rejecting same-sex unions. New York, California and 34 other states had legalized gay marriage. Georgia voters banned it in 2004.

That changed Friday, a day in which gay and lesbian advocates took to the streets in celebration. For them, Friday was a day of validation and vindication, filled with tears of joy and, in courthouses across metro Atlanta, hurried marriage vows.

For those who oppose same-sex marriage, the ruling was a defeat of biblical proportions. Many pastors said the high court defied Holy Writ, and they vowed not to officiate at gay marriage ceremonies. Some Georgia officials branded the ruling an intrusion into states’ rights and vowed to battle on in this culture war.

Writing for the majority, Justice Kennedy said, “The Fourteenth Amendment requires a state to license a marriage between two people of the same sex and to recognize a marriage between two people of the same sex when their marriage was lawfully licensed and performed out of state.”

Chief Justice John Roberts and Justices Antonin Scalia, Samuel Alito and Clarence Thomas dissented.

They argued — Scalia in often derisive terms — that the court had overstepped its authority.

“This court is not a legislature,” Roberts wrote. “Whether same-sex marriage is a good idea should be of no concern to us. Under the Constitution, judges have power to say what the law is, not what it should be. The people who ratified the Constitution authorized courts to exercise ‘neither force nor will but merely judgment.’”

‘I no longer feel second-class’

The split on the court seemed to mirror the deep fissure that runs through Georgia on this issue.

While cheers rang out at celebrations in Atlanta, the response was far more muted at the state Capitol.

Lt. Gov. Casey Cagle, a Republican, acknowledged the decision but was in no mood to celebrate it.

“My faith teaches me that marriage is between a man and a woman,” Cagle said. “I also understand the role of the Supreme Court under our Constitution. As we navigate this challenging issue, we must do so in a way that respects the deeply held religious beliefs of many like myself while also upholding the rule of law.”

State Sen. Mike Crane, R-Newnan, said he would probe the ruling for “weaknesses” that he and other critics of same-sex marriage could exploit.

“I don’t even like that word — ruling. It’s an opinion. It’s an opinion of five people that stands in absolute contrast to the majority vote by Georgians,” Crane said. “We have five members of the Supreme Court trying to set themselves up as the highest authority of the land. And I think they’re just wrong.”

Meanwhile, a surge of celebration drove people into the streets. The corner of Piedmont Avenue and 10th Street has been a preferred site of gay liberation gatherings, and was again. A rally downtown at the Center for Civil and Human Rights drew as many as 1,000 people.

Becca Sherrill recalled the way gays and lesbians were treated in Atlanta in the 1970s. When she joined protests, she said, police made it clear they would not protect her.

“It was very dangerous and we were really scared,” she said.

On Friday, she sat comfortably at the civil right’s center gathering with her spouse Leann Jones, whom she married in Washington, D.C.

“I never thought I was going to live to see this day,” Sherrill said.

Elsewhere, Richard Rice of Lawrenceville said that when he left the office Friday to go to the Gwinnett County courthouse and apply for his marriage license, his co-workers gave him a standing ovation. Rice, 52, married his partner of 11 years, Sandy Sanderlin.

He teared up as he spoke of being able to marry in his home state.

“I no longer feel second-class,” Rice said.

‘Our union is a little more perfect’

In Washington, several hundred people waving signs and flags in front of the Supreme Court erupted in jubilant cheering as news of the ruling emerged.

President Obama declared at the White House that “our union is a little more perfect. That’s a consequence of a decision from the Supreme Court, but more importantly it is a consequence of the countless small acts of courage of millions of people across decades who stood up, who came out, who talked to parents, parents who loved their children no matter what, folks who were willing to endure bullying and taunts.”

The court decision culminates what has been a rapid-fire acceptance of gay and lesbian lifestyles, driven by sympathetic movies, television programs and media reports that portrayed same-sex relationships with all the complexity and normalcy of heterosexual ones.

Attitudes toward gay marriage, perhaps more than any other issue of our time, have undergone an extraordinary evolution in this country in just 20 years, from broad condemnation in the 1990s to broad acceptance today.

A growing number of Georgians have shifted their opinion from a decade ago, when 76 percent of the state’s voters approved the state constitutional ban. A 2013 Atlanta Journal-Constitution poll found 48 percent of Georgians in favor of gay marriage versus 43 percent against.

'A slippery slope we're sliding on'

Still, the battles are hardly over. Some opponents say the decision strikes at the heart of not only what constitutes marriage, but also family.

“What the Supreme Court decided today will continue to undermine the family,” said the Rev. Don Hattaway, president of the Georgia Baptist Convention.

“This is a slippery slope we’re sliding on now,” added Hattaway, who is also senior pastor at the 3,000-member Tabernacle Baptist Church in Cartersville. “People from all kinds of deviant perspectives will want and now have the legal ground. … But the Supreme Court is not the ultimate court. There is an ultimate judge to whom we all must give an account of our lives.”

The court’s decision is expected to provoke a sharp response from many conservative lawmakers in Georgia, who predict sustained legal and political combat in 2016 and for decades to come.

Within several months, the ruling is sure to fuel the fight for “religious liberty” legislation that has failed to pass the last two years amid opposition from business interests. Social conservatives vowed to fight for years what they termed the “Roe v. Wade for marriage.”

'It's not gay marriage. It's equal marriage'

At the corner of Piedmont and 10th, people waved their American and rainbow flags with joyful fervor and hugs. Passing drivers honked their horns, and the crowd’s chants of “Love is love. Love is love” could be heard two blocks away.

Chris Baldridge of Atlanta, 22, came out when he was 16. He said this day was more exciting than he could have imagined. He said he’s never seen anything more beautiful than the straight and gay community coming together for this historic day.

“It’s not even gay marriage,” Baldridge said. “It’s equal marriage.”

The issue has long been settled for Max Dupree, who lives near Decatur and who married his partner three years ago in Boston. On Friday, though, he recalled a time when he was just a boy. After a well-known gay designer had died, he heard someone say, “Oh, he’s just a dead fag. Who cares?”

So many years later, the remark still hurts.

Friday’s decision helped.

“It’s just a big day,” said Dupree, 47, who lives near Decatur. “Our employers can’t deny our spouse benefits. It just brings a level of comfort in so many different ways.”

Dupree was vacationing in Florida on Friday, expecting to come home Sunday.

He wasn’t worried about missing any celebratory parties, though: “This one will go on for a while, I’m sure.”

Staff writers Sheila Poole, April Hunt, Leon Stafford, Arielle Kass, Aaron Gould Sheinin, Andria Simmons, Dan Klepal, Ty Tagami, Daniel Funke, Kristina Torres, Greg Bluestein, Daniel Malloy, Ernie Suggs, Rodney Thrash, Jennifer Brett, Janel Davis, Katie Leslie, Gracie Bonds Staples, Kendall Trammell and Jane Hammond contributed to this report.