Raleigh, North Carolina (CNN) At Pullen Memorial Baptist Church, the pews are packed with people who mostly do not share a history with the man they've come to hear. They rise when he enters the sanctuary at five minutes past 7 in the evening, and before he utters a single word, they give him a standing ovation.

Last year, two defiant minutes on the stage of the Democratic National Convention turned Khizr Khan into an unwitting celebrity, but he has held onto his humility.

He stands now before this North Carolina audience, slightly hunched in a dark navy suit and striped tie. He bows his head, brings his hands together in a perfect Namaste. The church lights illuminate a small pin on his lapel that says everything: Gold Star father.

His middle son, Humayun Khan, served in Iraq as a captain in the US Army and was killed in 2004 by a suicide bomber in Baquba. He is perhaps the best known of the Muslim American soldiers who have died in the wars in Iraq and Afghanistan.

It was the Khan family's sacrifice that cast a national spotlight on them. But it was Donald Trump's attacks on Muslims and immigrants that inspired Khan to speak out.

One year after Trump's election, Khan remains steadfast as a brown immigrant man grateful for everything America has given him -- and indignant as ever at the man who occupies the White House.

I meet Khan for the first time here in Raleigh, a stop on a promotional tour for his new book, a memoir of a Pakistani farmer's son who read Rumi by moonlight and eventually made it in America as a Harvard-trained lawyer.

Khan was born 12 years before me, but both of us grew up in similar cultural environments -- though my family in India never suffered the recriminations of life under dictatorship as he did in Pakistan. Especially sweet, I thought, were Khan's recollections in his book of meeting the beautiful woman in the yellow sari who would later become his wife. I know firsthand the limitations on courtship and dating in a conservative society.

For all the obvious reasons, Khan's book resonates with immigrants like me.

He writes of his love of the values and ideals cherished in America and his devotion to the US Constitution, a document now associated with Khan after his convention appearance. He first read it in a college class in Pakistan and was awed by the rights and freedoms afforded to every American: equal protection of law and dignity.

As their son's portrait flashed across the screen, Khizr and Ghazala Khan famously took on Donald Trump at the 2016 Democratic convention.

He was taken with a nation that gave its citizenry such birth rights, all the more so because he lived through martial law.

"I am an American patriot not because I was born here," Khan writes, "but because I was not."

Khan's deeply personal story gives heft to his examination of how we, in this age of acrimony and deep divisions, see ourselves as individuals -- and as a nation. Everyone who has come to hear him tonight, I am certain, will carry Khan's words with them, especially with another Veterans Day upon us.

Earlier, I'd sat with Khan in a downtown hotel lobby and talked about his son. I thought of all the Gold Star mothers, fathers and wives I had met while covering the Iraq War. I'd heard men like Robert Stokely, whose son Michael was killed in 2005, speak of the sacrifices of military families.

But Khan was the first man from my part of the world I'd heard speak in this vein. I asked him what message he has for America on Veterans Day.

"We live in one of the best countries on planet Earth," Khan told me.

"Every value of this country is worth defending, and we pay tribute on Veterans Day to those who have given and sacrificed their all in defense of this country. We are free today because of them. We are prosperous because of their sacrifices. We are custodians of their fairness and goodness. We remain a beacon of hope for the rest of the world because of their sacrifices.

"Had they not sacrificed their time, their life, their blood, and all abilities, we would not be here today."

I had often wondered if Khan had been worn down by the ugliness over the last year, not just toward Muslims and immigrants but toward him, specifically. I wondered if he thought now his son's sacrifice might have been in vain.

Far from it.

He had faith that the basic principles on which this country was founded would prevail in the end. It warmed my heart to learn Khan's hope had not frayed.

The Army gave the Khans a Gold Star Banner after their son, Capt. Humayun Khan, was killed in a suicide bombing in Iraq on June 8, 2004.

An American family

I watch Khan intently as he winds down this speaking engagement, his 165th since he famously took on Trump. He tells his audience about some of the experiences recounted so eloquently in "An American Family: A Memoir of Hope and Sacrifice."

If you read the book, you'll learn how he wrestled with his decision to appear at the convention. His family and friends warned him not to politicize his son's death, and he had decided to turn down the invitation to speak. But then he found a single envelope in his mailbox. There was no stamp, no return address. The handwriting belonged to a child.

"Dear Mr. Khan," the letter said. "You are a lawyer. Can you please not let them deport Maria? She is in fifth grade and she is our friend. Thank you."

Khan walked back to his house, to a room set up to pay tribute to Humayun's life. He stared at his son's photograph, at his deep, dark eyes, and asked himself: "What would Humayun do?"

If you read Khan's book, you will learn how he grieves for his son. How he and his wife, Ghazala, learned to go on with their lives, to "make peace with a specter we knew would never leave."

At the convention last year, Khan pulled out a pocket-size copy of the Constitution and addressed Trump: "Have you ever read the United States Constitution?"

"Have you ever been to Arlington Cemetery? Go look at the graves of brave patriots who died defending the United States of America. You will see all faiths, genders and ethnicities. You have sacrificed nothing -- and no one."

Trump dismissed Khan, suggesting he, too, had made many sacrifices. Trump even implied Ghazala Khan's silence on stage was because of female subservience expected in certain strains of conservative Islam. And a feud ensued in the media. More recently, that feud has continued with Khan's public criticism of the way Trump handled a phone call to the widow of one of four servicemen killed in Niger.

The family, says Khan, was not afforded the dignity and privacy they deserved. He lashes out, too, at Gen. John Kelly, Trump's chief of staff whose own son was killed in Afghanistan, for defending the president's handling of the situation.

"He knows how sensitive these moments are," Khan says. "No protocol was followed. The president is incompetent to speak to these families."

I can see the rage, no, disappointment, in Khan's eyes that the nation's commander in chief would speak to a Gold Star family this way. He could imagine how it must have compounded the family's shock, and the intense grief that followed.

A soldier's death cannot be politicized this way, Khan says. He wonders what the White House actions say about the moral compass of this nation.

Khan often visits his son's grave in Section 60 of Arlington National Cemetery. In his memoir, he writes about how he learned how to make peace with his grief.

Thank you for your service

After Khan's comments this evening, a few people line up at a microphone to ask him questions. The first comes from a man who begins: "Thank you for being here and where do I go to sign up for your Senate campaign?"

The second is more serious.

Shanna Ratashak has thought long and hard about what to ask Khan. The wife of a retired Army lieutenant colonel, Ratashak served on many an Army CARE team , responsible for helping military families deal with deaths and other crises. She has been to Army homes to console mothers, fathers, spouses. She could never truly know how the Khans felt in losing their son, but she felt she might be able to understand better than most.

She also knows this: that the biggest sacrifices military families make do not just take place on the battlefield. They happen quietly and without recognition, often at home: weddings canceled, celebrations postponed, children raised with one parent on long deployments. Only those left behind bear witness to these acts.

She feels America has forgotten its service members. So few are in the military these days. It wasn't like World War II or Vietnam, where everyone seemed to know someone in uniform. She feels people are generous with platitudes -- "thank you for your service" -- but don't understand what that service means.

When she saw Khan speak at the convention, she sat up and paid attention to the television. Finally, she thought, someone was speaking on her behalf.

"When he had the courage to get up and say, 'My son sacrificed for everyone,' it was so moving. It was giving all these families a voice," she tells me.

And when she learned Khan was speaking in Raleigh, she obtained a ticket, hoping she would be able to get away on a school night. She settled her kids and, before leaving home Tuesday evening, sat down to pen a letter.

"Dear Mr. Khan," Ratashak began writing on lined notebook paper.

'You touched the lives of many'

"I was so touched by your story ... by your courage. What an American story yours is, and it is the exact thing that makes our country great. It has always been great and does not need to be made great again. Your son's story reminds me so much of my husband's.

"Thank you for standing up to the hate of DJT, who should never be allowed to be commander in chief. It's a travesty to our service. May you know you touched the lives of many, and your son's service and sacrifice will always be remembered.

"I wish you beautiful memories of your son forever ... until you meet again."

Ratashak planned to give Khan the letter at a book signing after his talk. She didn't know if she would get that opportunity, so she stood in line to tell him instead.

She says she can't imagine losing a child at war and then have people at home not understand her sacrifice. She tells him she senses bitterness among veterans and their families that they are somehow not appreciated. She asks Khan for advice on what she ought to say to them.

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There are many in the audience eager to hear Khan's answer. Among them is the organizer of the event, Rene Martin, whose son completed three tours of Iraq. Each time, she lived in fear that she, too, would become a Gold Star parent.

Khan begins his answer to Ratashak by thanking her.

"First I humbly pay tribute to your family's service," he says.

"I am testament to the respect and dignity that this nation bestows on its men and women serving in the military and law enforcement. They are our heroes. Their families are our heroes. We cherish them. We respect them. They are our protectors."

He says his son wrote an essay once while he was still a young cadet. It was titled "Democracy requires vigilance and sacrifice."

"How true it is today," Khan says. "Our democracy, our democratic system of life requires vigilance because those who do not wish us well have attacked us and sown this division among us by exploiting some issues. This nation never forgets the sacrifice of its men and women in uniform. We are in debt."

He then tells the audience what I already know. That on Veterans Day, he will again visit Humayun's grave at Arlington Cemetery. In his book, he describes his son's headstone as "a slab of white marble with soft streaks the color of wood smoke" that has "a star nestled in a crescent moon" etched above his name, date of birth and date of death, the medals he received and the conflict in which he was killed: Operation Iraqi Freedom.

Khan visits his son often. He offers his prayers and then steps away to one corner of Section 60, 14 acres reserved for the casualties of America's most recent wars. He looks out over the rows and rows of neatly arranged headstones, all the sons and daughters who are buried there. He acknowledges their sacrifice. And that he lives in a free nation because of it.