Margaret Conway (L) is kissed by her wife Rea Carey after the US Supreme Court ruled on Friday that the US Constitution provides same-sex couples the right to marry at the Supreme Court in Washington June 26, 2015.[Photo/Agencies]

Chief Justice John Roberts, who for the first time in his 10-year-tenure read excerpts of a dissent from the bench, warned in his written opinion that "people of faith can take no comfort" in the ruling.

He questioned whether religious colleges could continue to restrict student housing to opposite-sex couples. Dissenting Justice Clarence Thomas went further, predicting churches would face demands to participate in civil marriages between same-sex couples.

Writing for the five-justice majority, Justice Anthony Kennedy emphasized that religious opponents "may continue to advocate with utmost, sincere conviction" that gay marriage is wrong. He noted that the Constitution protects religious people "as they seek to teach the principles that are so ... central to their lives and faiths."

It was a relatively brief reference in Kennedy's 28-page opinion, and it remains to be seen how constitutional principles might clash in future cases.