When lovers Sheri and Musa have a passionate fight in a diner, she throws coffee at him, and he offers to satisfy her by pouring the entire pot over his head. An act of dishonesty by Musa, a gentle Egyptian immigrant who drives a cab in this American city, has enraged Sheri, an impulsive, garrulous waitress with a different background. But when he holds the coffee pot up as if to pour, she climbs on a table to grab the pot. He clambers up, too. “You are my type for me,” he tells her tenderly in his slightly broken English. “I stand on the table with you.”

This disarming moment displays the major strength of “Pilgrims Musa & Sheri in the New World,” Yussef El Guindi’s distinctive, occasionally over-mellow cross-cultural romantic comedy. Now on view in a handsomely acted production from Mosaic Theater Company, the play thoughtfully ponders migration, assimilation and barriers to understanding between people of different heritages. But the characters are never mere markers of ethnic diversity or social niche: As cannily conjured by El Guindi, an Egyptian-born, Seattle-based playwright, they are idiosyncratic individuals richly endowed with quirks — such as these lovebirds’ eccentric manner of tabletop reconciliation.

Director Shirley Serotsky’s smooth production unfurls on a stylized set (designed by Nephelie Andonyadis) depicting a city made of suitcases. The visuals echo the international travels of Musa (a delightful Ahmad Kamal, channeling rumpled amiability); his spirited, decorous Muslim American fiancee, Gamila (a very good Sanam Laila Hashemi); and his roguish Somali friend, Tayyib (Gerrad Alex Taylor).

Then there’s Abdallah (Freddie Lee Bennett), Musa’s roommate, a Sudanese native who has gone missing while on the Hajj. A spooky figure who doesn’t interact with the other characters but appears now and then to deliver eloquent and sometimes funny musings on our global-village world, Abdallah is one of El Guindi’s most ingenious touches: The character lends the play valuable notes of somberness after the circumstances of his disappearance are revealed.

The most richly drawn character is Sheri (the vibrant Rachel Felstein), an endearing, emotionally scarred neurotic who appreciates Musa’s heritage and enjoys talking about God. After learning that Musa reads mystery novels to improve his English, Sheri wonders aloud whether the Supreme Being resembles a detective “and we’re like the sinners being investigated.”

Musa, a Scotch-drinking Muslim, views the deity as omniscient. “This is interesting idea but not true,” he responds to Sheri’s God-as-gumshoe notion.

Because of the buoyant atmosphere that prevails in “Pilgrims Musa & Sheri” — which is part of Mosaic’s Voices From a Changing Middle East Festival — and because all the characters register as such good-hearted, reasonable people, the narrative stakes aren’t always high enough to generate major suspense. No matter how the love triangle evolves, you sense that Musa, Sheri and Gamila will all be fine.

The view of America also is upbeat, not just celebrating diversity, but also cherishing the opportunities we have in this country — and beyond — to do whatever work it takes to empathize with different people. That vision is, needless to say, a salve at a time of bitter social, partisan and national divisions.

Optimism can have an abstract quality: Fortunately, “Pilgrims Musa & Sheri” is bracingly specific. We’re not the ones who get drenched with caffeine when the lovers quarrel, but watching these keenly individualized characters, we get an energizing jolt.

Pilgrims Musa & Sheri in the New World by Yussef El Guindi. Directed by Shirley Serotsky; lights, Brittany Shemuga; costumes, Danielle Preston; sound, Roc Lee; properties, Michelle Elwyn. About two hours. $20-$65. Through Feb. 16 at Atlas Performing Arts Center, 1333 H St. NE. mosaictheater.org.