— It’s been said that if you want to keep the peace at a friendly gathering with your in-laws (or anyone else for that matter), avoid discussions of politics or religion.

So it would seem doubly wise for politicians to steer clear of public pronouncements on religion — even more so in light of the whole separation-of-church-and-state thing. Yet they insist on venturing onto that thin ice, recently including a couple of Louisiana’s own.

It was actually the nation’s politician-in-chief, Democratic President Barack Obama, who got the ice cracking earlier this month in his speech to the National Prayer Breakfast. In discussing the threat posed by the Islamic State terrorist group, Obama cautioned against religious relativism, citing the Crusades, the Spanish Inquisition and segregation among deplorable acts carried out “in the name of Christ.”

That did not sit well with U.S. Rep. John Fleming, of Minden, a member of the prayer breakfast audience who said later on the radio that not only did Obama “vilify Christianity, but he actually made a case to defend radical Islam. ... He actually defended what they were doing and tried to draw some sort of twisted equivalency, moral equivalency, between what they’re doing today and what Crusaders did 800 years ago.”

Well, OK, the equivalency bit is maybe understandable — but Obama also described the Islamic State as “a brutal, vicious death cult” that commits “unspeakable acts of barbarism,” which is hardly a ringing defense. And the clear message of the speech was a condemnation of evil-doing justified on religious grounds of any sort.

Obama’s comments drew considerable fire from conservatives other than Fleming, including from Fleming’s fellow Louisiana Republican Gov. Bobby Jindal, who is seriously contemplating a run for the White House in 2016.

“Mr. President, the Medieval Christian threat is under control,” Jindal said in an interview with the National Journal and also tweeted on his Twitter account. “Please deal with the radical Islamic threat today.”

Jindal is no stranger to mixing politics and religion, and he seems to delight in plunging into the frigid waters. In his own speech to a prayer meeting, sponsored by the American Family Association last month in Baton Rouge, he affirmed, “Our God wins!”

Jindal did not define who his “God” is, exactly, but he has said he’s an evangelical Catholic; so, presumably, he believes in a trinitarian god expressed as Father, Son and Holy Spirit, in accordance with Catholic theology. If his God wins, then that suggests other gods lose — like, maybe the nontrinitarian God of the Unitarians or of the Jews, or the Gods of the Hindu faith of his childhood.

It would seem to go almost without saying that one of the losing gods is the Allah of Islam.

“Islam has a problem,” Jindal declared in a speech last month in London that has acquired considerable notoriety, in part for its widely discredited claim of Muslim “no-go zones” in Europe.

The London speech also included an extensive denunciation of violence by Islamic terrorists.

“How many Muslims in this world agree with these radicals?” Jindal asked. “I have no idea. I hope it is a small minority.”

Later he said, “I do continue to believe and hope that most Muslims oppose these bloodthirsty acts of terror,” a statement that at least gets just over half of the world’s 1.6 billion Muslims off the hook — maybe.

Consider if Obama were to declare that “India has a problem,” in reference to the more than 8,000 “dowry deaths” that occur there each year, including numerous bride burnings. India, of course, is the land of Jindal’s ancestors. It’s where he was conceived: His mother was pregnant with him in 1971 when she and her husband moved to Louisiana, where the couple still lives.

“How many Indians in this world agree with these practices?” Obama might say. “I have no idea, I hope it is a small minority.

“I do continue to believe and hope that most Indians oppose these bloodthirsty acts of oppression.”

In both the real Jindal scenario and the hypothetical Obama one, the issue is not whether terrorism or bride burning is deplorable: Both are and should be condemned. What’s objectionable is the back-handed impugning of potentially millions of members of a group for the actions of a few.

Gregory Roberts’ email address is groberts@theadvocate.com, and he is on Twitter, @GregRobertsDC.