The Mosaic Harmony choir, led by Rev. David North, performs as part of the 9th Annual 9/11 Unity Walk in Washington, D.C. (Amanda Voisard/For The Washington Post)

A microphone reverberated with the deep and sonorous Muslim call to prayer shortly before 2 p.m. Sunday. “Allaaaaaah — uh — Akbar!” An entire congregation bowed its head in prayer — a Jewish synagogue filled with Muslims, Jews, Christians, Buddhists, Sikhs, Hare Krishnas, Mormons, Pentecostals, Greek Orthodox, Baha’i and others.

Just think, one woman sitting in the mauve seats at the Washington Hebrew Congregation marveled, in another country, they all could be shot for such blasphemy.

But on Sunday, days before the nation commemorates the Sept. 11, 2001, terrorist attacks and as a bitterly divided Congress and country debate whether to authorize missile strikes against another Middle Eastern country, hundreds of Washingtonians gathered for the ninth annual 9/11 Unity Walk, seeking to find what people of different faiths share in common rather than what divides them.

Throughout the afternoon, Christians learned to chant with Hare Krishnas, carefully holding laminated mantras on their laps. Sikhs gave turban-tying demonstrations. Others practiced yoga and tai chi or danced in peace circles. The faithful or the plain curious could help the poor by bagging potatoes at St. Sophia’s Greek Orthodox church or making trail mix at the Embassy of the Vatican, open to walkers for the first time in honor of Pope Francis and his dedication to the poor.

“You should stay open more often,” Maryum Saifee, 31, a “cultural” Muslim who works at the State Department told the priest at the door as she left the Embassy of the Vatican. “The garden is really beautiful.”

A Syrian American who would only give his name as Wasim out of fear for his family still in that country, said he would never have imagined as a boy that he would be so comfortable in a synagogue, praying for peace, for an end to war, for President Obama not to drop bombs on his country, with others of so many different faiths.

“But I came to this country when I was 18, and I had a choice,” he said. “I had to let go everything I learned, about who my enemy was, or constantly be in pain.”

South African Ambassador Ibrahim Rasool, a Muslim, speaking at the synagogue, said he recalled the moment when he found a verse in the Torah, about God breathing life into the soul of each human, that was nearly identical to a verse he loved in the Koran. He realized that each person, no matter the religion, language or color, carried the spark of the divine, and he urged those on the Unity Walk to do the same.

And so, true to the motto of the walk: “From Different Paths, We Walk as One”, a Buddhist in saffron robes and sandals walked along Massachusetts Avenue with a Cambodian and a Presbyterian minister until they all decided to visit the Embassy Pentecostal Evangelical Church to hear believers speak in tongues.

The church was one of several houses of worship in Northwest Washington along the two-mile route from the synagogue to the Islamic Center of Washington that opened the doors to anyone and offered “faith guides” who could explain their beliefs.

Down the road, at the Sikh Gudwara, Dennis and Leta Kopp of Rockville — she a retired Christian chaplain — ate brown rice, lentils, chickpeas and yogurt with Saba Ahmed, a law student at American University in her traditional Muslim head scarf.

Ahmed was 16 on Sept. 11, 2001, she told them. All of a sudden, she said, people changed. They looked at her with suspicion. They distanced themselves. She found herself having to explain that yes, she was a Muslim, but no, she wasn’t a terrorist.

Instead of becoming angry, or isolating themselves, she said, her family began inviting people into their home and their mosque to teach them about their faith.

Dennis Kopp, a retired entomologist, told her how he worked with Israelis, Palestinians, Jordanians and Egyptians combating a virulent outbreak of white flies that were destroying cotton, tomato and cucumber crops. “They finally had an enemy they could hate more than each other,” he said.

When talk turned to Syria, as it did quietly throughout the day, Kopp turned to Ahmed and said: “I’m a dyed-in-the-wool Democrat and even I don’t want President Obama to go in and bomb Syria to pieces,” he said. “Because there’s going to be a 16-year-old that’s just going to be too close to one of those bombs. And she’s going to look an awful lot like you.”

Outside, a Sikh wearing a button that read: “Ask me why I wear a turban” handed out water and Coke. A Mormon, passing by, politely waved the Coke away, as Mormons do not drink caffeine.

Jim Gardiner, a Franciscan friar dressed in a simple brown robe tied with rope, finished his lentils, noting that in every religious tradition, the most significant events often centered on the sharing of food. The Last Supper. Jesus going to eat in various “unsavory” people’s homes. And from that sharing came understanding, he said.

It was that spirit, he said, that drew him to the Unity Walk. So often, religion is about converting other souls to the “One True Faith,” about destroying others who don’t believe the same things you do.

“Look, if you don’t think your religion isn’t the right religion, why are you in it?” Gardiner said. “But that doesn’t mean that everyone else is wrong. We’re out of that siege mentality now. Or at least I like to think that we are.”

With that, he continued south on Massachusetts Avenue, where the walk ended at the Islamic Center. A Mormon, a rabbi, an Episcopal bishop and a Buddhist said blessings. The day ended with the Jewish Shofar sounding amid the minarets of the mosque.