Arjun Sethi is a lawyer in Washington.

Those looking for answers in the wake of Sunday’s shooting at a Sikh temple in Oak Creek, Wis., might recall the words of the African American poet Langston Hughes: “I swear to the Lord I still can’t see why democracy means everybody but me.”

Mistaken for Muslims because of their turbans and beards, Sikhs have repeatedly emerged as a target of bigots intent on revenge for the Sept. 11, 2001, terrorist attacks. Although the monstrosity of a few days ago is, thankfully, rare, the lack of understanding that generated it is all too familiar.

Being a Sikh in the United States has never been easy. Although Sikhism is the world’s fifth-largest religion, with about 500,000 followers in the United States, Sikh children are bullied and taunted because of their head coverings. When I was in elementary school in the 1980s, I was regularly shoved into the girls’ bathroom because of my long hair. I recall lying face down on the floor with my hair unfurled, wondering when the senseless harassment would stop.

For many of us, the harassment hasn’t stopped, and 9/11 only made it worse. When I worked as a paralegal in New York in the years immediately after the attacks, I was repeatedly singled out by court officers and asked for photo identification. My colleagues would enter courtrooms without a hitch. Only three weeks ago, a man in West Virginia stared me down and refused to ride in the same elevator.

Still, I am one of the lucky ones. Just days after the 9/11 attacks, 49-year-old Balbir Singh Sodhi was gunned down in Phoenix because he was mistakenly thought to be Muslim. In July 2004, Rajinder Singh Khalsa was beaten unconscious in New York by white men. In March 2011, Gurmej Singh Atwal and Surinder Singh were fatally shot in Elk Grove, Calif., during an afternoon stroll. Countless other Sikhs have been victims of hate crimes, the casualties of unbridled ignorance.

The shooting Sunday was not the first instance in which Sikh places of worship have been targeted. In March 2004, a gurudwara in Fresno, Calif., was vandalized. A few months ago, a gurudwara under construction in Sterling Heights, Mich., was defaced.

Sikhs aren’t Muslim. Sikhism is an independent faith that emerged in the 15th century, hundreds of years after Islam. But that’s not the point. Muslims have been unfairly targeted, too, and have endured numerous attacks and bias-related incidents.

Americans face a choice: We can look at these events in isolation, or we can have the courage to call them what they are: a threat to the promise of the United States.

This country’s commitment to equality — and to the promise of a nation that is not just characterized by diversity but also defined by it — is what drives immigrants here and what makes the United States the envy of the world; it’s what led my parents to emigrate here from India more than 40 years ago, leaving behind more than I can imagine.

Fighting bigotry is the responsibility of every American. Our nation is home to more than a thousand hate groups, according to the Southern Poverty Law Center, and the number is rising. There are steps ordinary citizens can take, including working within their communities to understand the causes of bigotry, including xenophobia, economic frustration and consternation over the U.S. population’s evolving racial demographics. They can encourage hate crimes to be reported, and parents can coordinate with schools so that our youths understand and appreciate Muslim and Sikh students.

The government must play a part as well. Since 2001, the Sikh Coalition reports, more than 700 Sikhs have been the victims of hate crimes. It’s appalling that the FBI form for reporting hate crimes has options to record incidents against Catholics, Protestants, Jews, Muslims, agnostics and atheists but not Sikhs. Sikhs who have beards and wear turbans are prohibited from serving in the Army unless they are granted an exemption — despite the fact that Sikhs have fought alongside other Americans for decades. Is there a better way for this country to embrace diversity and fight bigotry than for observant Sikhs to be allowed to serve on the front lines?

Our faith has a long history of embracing others. The Sikh holy book contains the writings of Muslims and Hindus, and Sikh temples are open to members of other faiths. Sikh temples in India are famous for their “langar” halls, where food is available all day, every day, to those in need. And the Sikh prayer that concludes all religious ceremonies closes with a blessing for all mankind.

The doors of Sikhism are open. Will Americans take steps to ensure that this country’s doors remain open, too?