“How’s our unity event gonna compete with this!?” I’d lamented on the No. 5 train reading that combined presidential campaign spending topped $1 billion for partisan advertising, transportation polling and something called “ground game.” “Our budget’s 500 — bucks, not millions!” Promoting a screening of anti-polarization documentary “Undivide Us” at Brooklyn’s Plymouth Church, my “ground game” was pedaling a Citi Bike tying flyers to wrought iron fences. “Thank God God’s on our side,” joked a co-sponsor. “Pray for loaves, fishes and a bargain sound engineer,” I’d laughed. Earlier this fall, we’d invited Brooklyn Heights’ diverse interfaith league — churches, synagogues, mosques — to co-host an Oct. 27 day of unity before the volatile presidential election. We’d screen the film, mount a community tea party and model faith, freedom and good citizenship, regardless of outcome. “America is at a crossroads,” I’d emailed. “Houses of worship can help. Disagreement is not division.” Several co-sponsors committed volunteers,100 tea sandwiches and homemade sweets. Other congregations will publicize, attend and join in community prayer. The film, touring nationwide in grass-roots events, gathers regular Americans in deeply divided Arizona, Pennsylvania and Georgia to discuss volatile issues like guns, education and abortion. I met filmmaker Kristi Kendall, a former “20/20” ABC News producer, at a CUNY screening by depolarization group Braver Angels. I proposed a novel inter-faith version. After the film, we’ll host an audience Q&A on bridging the divide. Tony Woodlief’s book “I, Citizen,” inspired Kendall’s film. Woodlief urges the people to battle the “political rage machine” and reclaim self-governance and common ground. Onscreen, he speaks powerfully of a poor childhood where a “neighbor lady” slipped him $100 for food. The premise: flip conventional notions of division by offering constructive, humanizing dialogue. Average Americans participate in mediated sessions modeling how to be citizens. They share reasoned perspectives of neighbors first, then their own. Focus shifts from the loudest 20% skirmishing in rallies, protests and sometimes political violence who truly cannot agree, and engages instead the quieter 80% of citizenry holding space for other views. Finding a common spark in each other is spiritual, covenantal, elevating the quietly humble among us. Houses of worship can work with that. We expected Halloween competition from ghouls and goblins, but then Trump/Vance announced its same-day Madison Square Garden rally. Fingers crossed Harris/Walz won’t book Yankee Stadium during the World Series. Our humble 100-seat spread won’t be much competition for any candidate’s 20,000-plus partisan arena shindig. We’ll have American flags — ours planted in recycled BloomAgainBklyn flower arrangements. The Harris campaign spent $18,500 on lattes and Trump’s nearly $71,000 on Big Macs, but local merchants donated our Ceylon tea. A gaggle of faithful will shear crusts from tiny sandwiches — tuna (Catholics), egg salad (Congregationalists), lox and schmear (Jews), PBJ (Unitarians) and chicken salad (Episcopalians). There’ll be baklava and za’atar pita. I’ll bring cucumber, pimento cheese and my grandmothers’ tea pots. Our communications consultants are a teen journalist and local caregiver filing Brooklyn Heights blog dispatches. Our $500 budget covers overtime janitors and quality amps. And, importantly — priceless, even — clergy from every faith are invited to pray in community for national unity. I’ve invited both candidates. They should come. Plymouth’s history is storied. In 1859, Illinois statesman Abraham Lincoln accepted its telegram lecture invitation (budget: $200). The speech, moved at the last minute to Manhattan’s Cooper Union, launched his 1860 presidential campaign. Lincoln visited Brooklyn to hear its famous preacher, abolitionist Henry Ward Beecher, twice on that trip. We gave him a pew. No one knows which candidate will prevail in November, but likely nearly half of Americans will be disappointed. But there’s good news. A recent AP/NORC poll shows 9 in 10 agree on most fundamental rights and 84% support freedom of religion. Faith communities and regular citizens can, as “Undivide Us” participant and George Mason University Prof. Ben Klutsey suggests, “give grace to one another.” I have faith community events can help. America has been here before. Need proof? Look behind the film screen. Emblazoned above the fireplace is the gilded dedication from coffee magnate John Arbuckle — the prior century’s version of today’s technology entrepreneur politicker. He donated the buildings, grateful for “what [Plymouth and Beecher] did to preserve the union.” Today’s democratic stakes are also high. “Not on my watch,” I’ll whisper to my grandmothers and church ancestors at the opening. Then I’ll read Psalm 133: “Behold, how good and how pleasant it is for brethren to dwell together in unity!” I pray our tiny effort will be a start. Koster is a New York lawyer and writer.