(Charles Dharapak/Getty Images)

Martin Luther King’s teachings are as relevant as ever, in this day when politics in America have become sharply polarized and people appear to be losing faith in our institutions, President Obama said today at the official dedication of the civil rights leader’s monument on the national mall.

“I know we will overcome,” Obama said, standing next to the memorial, which includes a 30-foot statue of King. “I know there are better days ahead. I know this because of the man towering over us. I know this because all he and his generation endured.”

Obama, the nation’s first black president, told a large crowd that the King memorial is a monument to the collective achievement of the civil rights generation. He said that without King’s work, specifically his “I Have a Dream” speech on the national mall, the country might not have had the courage to overcome segregation and Jim Crow laws.

“Because of Dr. King’s moral imagination, barricades began to fall and bigotry began to fade, and the doors of opportunity swung open for an entire generation,” said Obama, who was 7 years old when King was killed.

The president said he hopes his two daughters take away from the monument a faith in what they can accomplish when they are determined and working for a righteous cause.

“This sculpture, massive and iconic as it is, will remind them of Dr. King’s strength, but to see him only as larger than life would do a disservice to what he taught us about ourselves,” he said.

“He would want them to know that he had setbacks, because they will have setbacks,” Obama said. “It was precisely because Dr. King was a man of flesh and blood and not a figure of stone, that he inspires us so. His life, his story tells us that change can come if you don’t give up.”

The president tried to connect King’s message to the present, sharing what he thinks King would tell Americans.

“At this moment, when our politics appear so sharply polarized, faith in our institutions so greatly diminished, we need more than ever to take heed to Dr. King’s teachings,” Obama said.

“If he were alive today, I believe that he would remind us that the unemployed worker can rightly challenge the excesses of Wall Street without demonizing all who work there. That the businessman can enter tough negotiations with his company’s unions without vilifying the right to collectively bargain,” he said. “He would want us to know that we can argue fiercely about the proper size and role of government without questioning each other’s love for this country.”

Obama also reminded the crowd that the progress King helped create did not happen overnight.

“It is right for us to celebrate Dr. King’s marvelous oratory, but it is worth remembering that progress did not come from words alone. Progress was hard,” the president said. “Progress was purchased through enduring the smack of billy clubs and blast of fire hoses. It was built through stays in jail cells. Nights of bomb threats.”

(LADEN ANTONOV/AFP/Getty Images)

Before his remarks, Obama and his family walked the walls of the monument along with members of King’s family.

Connecting his own legacy to that of King, Obama placed a signed copy of his presidential inauguration address and a signed copy of his 2008 Democratic National Convention speech in Denver into a time capsule at the memorial. Obama accepted the Democratic Party’s nomination for president in 2008 on the 40th anniversary of King’s “I Have a Dream” speech.

Many of those who attended the dedication, were moved by King’s legacy.

“It is a powerful message of hope – that we are making headway – that we are making some change – It’s slow,” said Tommie Muhammad, 39 , of Atlanta, Ga. ”We’ve got a long way – a long way to go – but it’s a progression in the right direction.”

Christi Syrdahl of Brooklyn, N.Y. said the King’s messages left a lasting impression on her.

“It’s not really about what your color is, it’s about how you feel about being one person in the United States and it really spoke to me,” she said.

ABC News’ Sarah Herndon contributed to this report.