The president asked, "Rather than pointing fingers or assigning blame, let us use this occasion to expand our moral imaginations, to listen to each other more carefully, to sharpen our instincts for empathy and remind ourselves of all the ways our hopes and dreams are bound together. ... Let's make sure it's not on the usual plane of politics and point scoring and pettiness that drifts away with the next news cycle."
You can read the president's full remarks HERE and click here for full ABC News coverage of the tragedy in Tucson.
President Obama's speech was a part of a hour-long program that included music, moments of silence, prayers and other speeches held at McKale Memorial Center at the University of Arizona in Tucson.
A Native American blessing opened the program followed by a welcome speech from University of Arizona President Robert N. Shelton, Arizona Gov. Jan Brewer and two student speakers from the university.
The president honored each of the victims: Judge John Roll, Dorothy Morris, Phyllis Schneck, Dorwan Stoddard, Christina Taylor and Gabe Zimmerman, the only of Giffords' staff members to perish in the shooting.
The president also praised those who saved others -- the nurses, doctors, policemen, staffers and bystanders.
"They remind us that heroism does not require special training or physical strength. Heroism is here, all around us, in the hearts of so many of our fellow citizens, just waiting to be summoned -- as it was on Saturday morning," the president said.
He also spoke about Christina Green, the third grader who was inspired by her early interest in politics to go visit her congresswoman only to get caught in the crossfire.
Her funeral is set for today.
Obama used Christina's example to make the case that America needs to tone down its sometimes venomous national discourse.
"Imagine: Here was a young girl who was just becoming aware of our democracy; just beginning to understand the obligations of citizenship; just starting to glimpse the fact that someday she too might play a part in shaping her nation's future," the president said. "She saw all this through the eyes of a child, undimmed by the cynicism or vitriol that we adults all too often just take for granted."
Green was born on Sept. 11, 2001, one of 50 babies born that day featured in the book "Faces of Hope."
The president highlighted that within the book, on either side of Green's photo, were the words, "I hope you help those in need. I hope you know all of the words to the National Anthem and sing it with your hand over your heart. I hope you jump in rain puddles."
The president concluded: "If there are rain puddles in heaven, Christina is jumping in them today. And here on Earth, we place our hands over our hearts, and commit ourselves as Americans to forging a country that is forever worthy of her gentle, happy spirit."
The president and first lady were greeted at the Tucson memorial by a standing ovation as they walked into the packed stadium.
"I have come here tonight as an American who, like all Americans, kneels to pray with you today, and will stand by you tomorrow," the president told the crowd.
Gifford's husband, space shuttle Capt. Mark Kelly, sat between the first lady and Secretary of Homeland Security Janet Napolitano.