Figurines are depicted in an embrace as part of the wedding cake display at Masterpiece Cakeshop in Denver, Thursday, June 6, 2013.

 (AP Photo/Brennan Linsley)

Posted 9 a.m. | Updated 4:30 p.m.

A suburban Denver bakery owner was not justified in his refusal to make a wedding cake for a gay couple, the Colorado Court of Appeals ruled on Thursday.

Jack Phillips, the owner of Masterpiece Cakeshop in Lakewood, refused to make a wedding cake for gay couple David Mullins and Charlie Craig in 2012, citing his Christian beliefs. Phillips' attorney argued that creating a wedding cake is more personal than making cookies and thus protected by the First Amendment.

The case has helped ignite a passionate debate between gay rights supporters and religious freedom advocates. Gay couples have won similar cases in other states.

Mullins and Craig sued Phillips, and last year the Colorado Civil Rights Commission ruled in favor of the gay couple. 

In its ruling Thursday, the appeals court agreed with the commission. 

Masterpiece argues that wedding cakes inherently convey a celebratory message about marriage and, therefore, the Commission’s order unconstitutionally compels it to convey a celebratory message about same-sex marriage in conflict with its religious beliefs.

We disagree. We conclude that the Commission’s order merely requires that Masterpiece not discriminate against potential customers in violation of [the Colorado Anti-Discrimination Act] and that such conduct, even if compelled by the government, is not sufficiently expressive to warrant First Amendment protections. 

Designing and selling a wedding cake doesn't convey a celebratory message about gay marriages, the court concluded.

"[T]hat message is more likely to be attributed to the customer than to Masterpiece," the court wrote in the ruling. "... Masterpiece does not convey a message supporting same-sex marriages merely by abiding by the law and serving its customers equally."

"Marriage equality issues have helped bring this to the forefront and helped people understand not only their obligation as business people, but also their rights as citizens, that they don’t have to move to the back of the bus," said Attorney Paul Greisen, who's representing the gay couple. 

Phillips faces fines if he refuses to make wedding cakes for gay couples -- he's stopped making wedding cakes altogether while the case is pending. And he says he will appeal to the state Supreme Court, and potentially even the U.S. Supreme Court if necessary.

"Somebody has to be able to take this thing to the court and prove that the Constitution is a valid document," he said, reacting to the news. "We do have rights that last all day, every day. They don’t stop when we open our shops."

CPR's Megan Verlee contributed to this report.