‘God save the United States and this honorable court.” Even with all the cynicism in our politics, that prayer is still the traditional announcement of the opening of a session of the highest court in our land.

And it’s starting to look like one good deed begets another. The Supreme Court under Chief Justice Roberts is well on its way to becoming a historic champion of religious freedom.

That is the outlook after justices on Monday blocked Missouri from denying a grant for safe playgrounds to a church school. The subsidy, for paving playgrounds with recycled tires, had nothing to do with religion.

The case won’t secure the reputation of the Roberts court in a fell swoop. Not the way, say, Brown v. Board of Education secured the reputation of the court led by Chief Justice Warren.

The long legal battle for religious freedom has been taking place in small-to-medium sized legal skirmishes all over the country. With the Missouri case, the hugeness of the trend is starting to become clear.

The “Show Me” state, the court ruled, can’t discriminate against religious people by denying them non-religious support everyone else gets. It would violate the free exercise clause of the First Amendment, the court ruled.

It also would have turned Christians — and those who choose to go to other religious schools — into second-class citizens. So more than playground paving was on the line in Missouri.

The court ruled by a solid majority of seven to two. The only dissenters were Justices Sonia Sotomayor, who seems to grow angry at the idea of unfettered religious practice, and the constitutional crabapple Ruth Bader Ginsburg. (Only a few months ago, Ginsburg joked that were Donald Trump elected president she’d quit America for New Zealand. She probably didn’t know that the head of state in New Zealand must swear he is a Protestant.)

Trinity Lutheran, in any event, would be a satisfying case in and of itself. But it’s part of a string of cases in which the Roberts court has vindicated religious Americans — often by astonishing majorities.

The trend began to emerge in 2012, when the court blocked federal authorities from trying to apply equal-employment law to the hiring of church ministers. That case, known as Hosanna-Tabor v. Equal Employment Opportunity Commission, was unanimous.

Several key cases followed. In one, the court ruled that the Upstate New York town of Greece was within its rights to permit volunteer chaplains to open town meetings with a prayer. The New York Times editorial board nearly fainted.

Then came the Hobby Lobby case. That’s where the Court exempted the religious owners of a closely held retail chain of craft stores from the contraceptive mandate that was put into effect by the Department of Health and Human Services after ObamaCare’s passage.

That puzzler divided the court five to four — and infuriated the godless left. That’s because it seemed to suggest that a capitalistic corporation could have religious views, as if the family owners didn’t matter.

The Court’s secularist wing buckled, though, before the Little Sisters of the Poor. The doughty nuns who care for the elderly poor finally won their right not to be entangled in the birth-control mandate in a unanimous ruling by the Nine.

What was President Barack Obama thinking? Someday historians will try to divine how much the Democrats were damaged at the polls by their wholly gratuitous attempt to bully a charity named Little Sisters of the Poor.

Not that the fight is over. The court flinched last year from hearing the appeal of a Washington-state pharmacist, Greg Stormans, seeking shelter under the First Amendment against the state’s attempt to force him to sell an abortion drug.

The same day the court ruled for Trinity Lutheran, though, it agreed to hear the case of the wedding cake baker, Jack Phillips, under fire from the Colorado Civil Rights Commission for refusing to bake a cake for a same-sex marriage. Must such a religious person chose between God and Colorado?

It’s hard to predict how the Court will rule in that case, which will be heard in the fall. It’s not hard, though, to forecast that if the justices do rule for the rights of the religious baker, they will extend a remarkable trend.

And answer the prayer to God for the salvation of their honorable court.

This column originally appeared in the New York Post.