This is to all the doubters and deniers out there, the ones who say that heaven on Broadway does not exist, that it’s only some myth our ancestors dreamed up. I am here to report that a newborn, old-fashioned, pleasure-giving musical has arrived at the Eugene O’Neill Theater, the kind our grandparents told us left them walking on air if not on water. So hie thee hence, nonbelievers (and believers too), to “The Book of Mormon,” and feast upon its sweetness.

Now you should probably know that this collaboration between the creators of television’s “South Park” (Trey Parker and Matt Stone) and the composer of “Avenue Q” (Robert Lopez) is also blasphemous, scurrilous and more foul-mouthed than David Mamet on a blue streak. But trust me when I tell you that its heart is as pure as that of a Rodgers and Hammerstein show.

That’s right, the same Rodgers and Hammerstein who wrote the beloved “Sound of Music” and “King and I,” two works specifically (and deliciously) referenced here. Like those wholesome, tuneful shows, “The Book of Mormon” is about naïve but plucky educators set down in an unfamiliar world, who find their feet, affirm their values and learn as much as they teach.

Of course different times call for different contexts. So instead of sending a widowed British governess to a royal court in 19th-century Siam or a nun in training to an Austrian chateau, “The Book of Mormon” transports two dewy missionaries from Salt Lake City to 21st-century Uganda.