“But just remember what the scripture says,” Bill Clinton urged in his speech accepting his party’s nomination for the presidency in 1992: “Where there is no vision, the people perish.”

It was a clever way for a moderately liberal Democrat, distrusted by a substantial number of religious believers, to show some familiarity with biblical language. I don’t know if it worked, but I doubt it. The line’s context — it comes from Proverbs 29:18 — made it an awkward fit. The word translated by some English versions as “vision” (Clinton, to his credit, quoted from the King James version) refers to God’s revelation; it has nothing to do with bold plans for the future enunciated by a political leader. Clinton was, however unintentionally — or maybe intentionally — equating his own political aims with divine revelation. Many religious folk, already wary of this preacher-like liberal, were likely to sense something amiss.

The trouble with politicians using biblical quotations is this: It’s hard, and most of them think it’s easy. The Bible-quoting politician usually ends up sounding self-important, disingenuous, ill-informed or all three at once. The quotation almost always sounds contrived, as if it’s been dropped into the speech because the audience expects something religious or spiritual, not because it clarifies or illustrates an important point.

It’s a temptation plenty of 2016 contenders are also falling victim to.

When Marco Rubio launched his presidential campaign in April, he capped it off with a biblical line. “In this endeavor, as in all things,” he said, “I find comfort in the ancient command to ‘be strong and courageous! Do not tremble or be dismayed, for the Lord your God is with you wherever you go.’” Well, okay. But the lines, from the Book of Joshua, are spoken by God himself to Joshua just before the Israelites make their way into Canaan, the promised land. Being strong and courageous is always a fine thing, but if the Lord is with Marco Rubio in anything like the sense in which (according to the text) he was with Joshua, why are we bothering to have an election?

John Kasich, in his campaign launch speech in July, said this: “You know, we got this Holocaust Memorial [on the Ohio State House grounds], and there’s a line etched that says, ‘If you save one life, you’ve changed the world.’ Do you believe that? Do you believe that? If you save one life, you changed the world. And the Lord will record what you’ve done for another in the Book of Life.” The line about saving one life, as Slate’s Joshua Keating pointed out (after Kasich used the line on a separate occasion), is a slight misquotation. It’s from the Talmud: “If you save one life, it is as if you saved the world.” The last line, though — “And the Lord will record what you’ve done for another in the Book of Life” — seems to be an invention. The phrase “Book of Life” appears eight times in the New Testament; Kasich’s line bears little resemblance to any of them.

Ben Carson, despite his appeal to religious conservatives, doesn’t often quote the Bible in his speeches and interviews. But when asked what sets him apart from Donald Trump, Carson said, in his typically soft-spoken style, “I’ve realized where my success has come from, and I don’t in any way deny my faith in God. ‘By humility and the fear of the Lord are riches and honor and life,’ and that’s a very big part of who I am. I don’t get that impression with him [Trump]. Maybe I’m wrong, but I don’t get that.”

That’s nicely done. The verse, from Proverbs 22:4, is not especially well-known, and Carson’s use of it seems pretty accurate. Contrast that with Trump’s attempt to invent a Bible verse on the spot. He told an evangelical interviewer that his favorite book of the Bible is “Proverbs, the chapter ‘never bend to envy.’” “I’ve had that thing all my life where people are bending to envy.” The phrase “bend to envy” is nowhere in any translation of the Bible. Nor is it any other text that I could find. (The Post wrote about this back in September.)

Jeb Bush, speaking at a commencement speech at evangelical Liberty University in Lynchburg, Va., last May, alluded to the widespread belief (as he says it is) that Christianity is a “static faith.” Bush observed that he could not “think of any more subversive moral idea ever loosed on the world than ‘the last shall be first, and the first last.’” It’s an odd line to use by a man seeking the highest office in the land, but there’s nothing egregiously wrong with Bush’s use of it. Yet the actual verse — from Matthew 19:30 — has it the other way around: “the first shall be last, and the last first.” The slight mangling of the text – along with Bush’s characterization of Jesus’s words as a “subversive moral idea” — would have sounded slightly wrong to the evangelicals in his audience.

Presidential candidates speaking at Liberty must feel obliged to allude knowingly to famous biblical passages. Bernie Sanders tried it when he spoke there in September. “I am motivated,” he said, “by a vision that exists in all the great religions — in Christianity, in Judaism, in Islam, in Buddhism and other religions. And that vision is so beautifully and clearly stated in Matthew 7:12, and it states: ‘So in everything do to others what you would have them do to you for this sums up the law and the prophets.’” Some will object that the “golden rule” has to do with individual conduct, not governmental policy, but leave that debate to one side. It’s not quite true that the rule appears in Judaism, Islam, Buddhism “and other religions.” Injunctions in those other religions are negative — i.e., do not do to others what you would not want them to do to you — as I suspect a fair number in the audience must have known.

Sanders’s speech was otherwise well-executed, but the use of this famous verse strikes me as a little too predictable — rather like a politician addressing the Shakespeare Society and using the line, “To be, or not to be, that is the question.”

Hillary Clinton does not share her husband’s facility with biblical texts, but she will use them from time to time. There is something slightly predictable about her biblical allusions, too, though. Asked by the New York Times to name the book that made her who she is today, she replied: “At the risk of appearing predictable, the Bible was and remains the biggest influence on my thinking. I was raised reading it, memorizing passages from it and being guided by it. … I still find it a source of wisdom, comfort and encouragement.”

Saying “at the risk of appearing predictable” doesn’t make your remark less predictable, but fair enough. Her answer would be slightly more credible, though, if once in while she quoted a non-famous biblical passage and said something non-obvious about it. In an interview with David Muir on ABC News in September — the topic the pope’s visit to the United States — Clinton remarked: “One cannot read the Sermon on the Mount without thinking that we all have to be more humble. We all have to be more kind and respectful. We all have to try to do more to help our fellow men and women. And I think that the pope is emphasizing the words of Jesus Christ. Emphasizing the high priority given to the poor. The priority of caring for those who are in trouble.” Well, fine. But anybody who knows anything about the Bible at all could have made the same boilerplate comment. You expect more from a politician who was raised reading the Bible, memorizing passages from it, and who is still guided by it.

Presidential candidates speak every day in a vast array of forums and settings, and I’m sure I’ve missed some of their biblical references that aren’t available online. Even so, one generalization does suggest itself, namely, that the candidates who might be expected to drop the most biblical quotations into their speeches — Carson and Ted Cruz — generally don’t. Carson speaks mainly about his own biography and general cultural trends. The one reference I’ve found (above) was mentioned in response to a question; otherwise he’s not a prolific Bible quoter. And Cruz, for his part, spoke at the aforementioned Liberty University — indeed he announced his candidacy there — and didn’t quote the Bible at all.

You wouldn’t expect Chris Christie or Martin O'Malley to use biblical quotations, and they don’t, from what I’ve been able to find. You would expect Carson and Cruz to use them, and for the most part they don't. Maybe these candidates know something that many of their competitors fail to grasp: that their listeners won’t be impressed by clumsy and superficial uses of sacred words.