LOUSIVILLE, Ky. (WHAS11) - More than 15,000 packed inside the KFC Yum! Center in downtown Louisville to honor Muhammad Ali on Friday. Ali died on June 3 from complications related to Parkinson's.

His wife, Lonnie Ali, was the first family member to take the stage to deliver a eulogy, following a number of speakers.

She said Ali taught others that adversity can make people stronger, but adversity can't take away dreams. Lonnie Ali also spoke of how Muhammad Ali got into boxing.

"Joe Martin handed young Cassius Clay the keys to a future in boxing he could scarcely have imagined.

"America must never forget that when a cop and an inner city kid talk to each other, then miracles can happen," Lonnie Ali said.

She said that the family has been humbled by the outpouring of support and heartfelt expressions of love.

Ali's widow, Lonnie, in her first public remarks since his death, took the stage in an oversized hat that shielded her eyes.

"Muhammad indicated that when the end came for him, he wanted to use his life and his death as a teaching moment. He wanted to remind people who are suffering that he had seen the face of injustice," she said. "He never became bitter enough to quit or engage in violence."

The celebration of his life came after a more than two-hour processional through city streets, that brought his body from a funeral home to the Cave Hill Cemetery.

The memorial service, lasted around three hours, featured a number of notable speakers, including former President Bill Clinton, Billy Crystal and Bryant Gumbel -- all scheduled to speak at the end of the program.

Former President Bill Clinton called Muhammad Ali a "man of faith" who took "perfect gifts we all have" and released them to the world.

"Being a man of faith, he realized he would never be in full control of his life. Something like Parkinson's could come along," Clinton said. "But being free, he realized that life was filled with multiple choices. It is the choices that Muhammad Ali made are what brought us all here today."

Clinton noted that Ali never felt self-pity because of the Parkinson's disease he battled for three decades, and said he continued to give himself to the world as "a universal soldier for our common humanity" long after his diagnosis.

"I think Ali decided at a very young age to write his own story," Clinton said. "He never got credit for being as smart as he was."

Billy Crystal drew fast laughs when he took to the stage at the memorial service.

"We're at the halfway point," he joked. The memorial has been underway for more than two and a half hours after a morning full of remembrances.

He joked that he was clean shaven when the day's activities began.

Crystal called the boxing great "a tremendous bolt of lightning, created by Mother Nature out of thin air, a fantastic combination of power and beauty.

"We've seen still photographs of lightning at the moment of impact, ferocious in its strength, magnificent in its elegance. And at the moment of impact it lights up everything around it so you can see everything clearly. Muhammad Ali struck us in the middle of America's darkest night."

"Ali forced us to take a look at ourselves. This brash young man thrilled us, angered us, confused us, challenged us, ultimately became a silent messenger of peace and taught us that life is best when you build bridges between people and not walls."

TV journalist Bryant Gumbel says Muhammad Ali went from being one of the most polarizing figures to one of the most beloved.

And, Gumbel says, he did it without changing his nature or compromising his principles.

"He gave us levels of strength and courage we didn't even know we had. Hating people of color is wrong, Ali said, and it doesn't matter who does the hate. It's just plain wrong."

The service began with a Quranic recitation by Hamzah Abdul Malik.

Translated in English, it means:

Truly those who say, "Our Lord is God" and are upright, the Angels will descend upon them saying, "Have neither fear nor sadness, but rather rejoice in this Paradise that you had been promised. We are your allies in this lower life and in the Hereafter, where you will have your hearts' desire, and you will have whatever you ask for, hospitably from One, Most Forgiving, Most Merciful. Who is more beautiful in speech than the one who invites to God and does righteous works, saying, "Truly, I am submitted to God"? For good and evil are not equal: repel ugliness with beauty, and behold, the one between you and whom there was enmity is transformed into a warm friend. But no one arrives at this station without great patience and immense fortune.

After the opening, a number of speakers took to the stage, to share their memories of Ali, and to encourage others to carry on his work.

Dr. Rev. Kevin Cosby was the first to speak, reminding people that before "before James Brown said ,'I'm black and I'm proud,' Ali said ,'I'm black and I'm pretty.' Blacks and pretty were an oxymoron."

Cosby was followed by Sen. Orrin Hatch (R-UT), who said that Ali was the Greatest ""because he reminded us who was the greatest -- God, our creator."

Rabbi Michael Lerner, who left the stage to thunderous applause, gave a passionate speech about politics in the U.S.

"The way to honor Muhammad Ali is to be Muhammad Ali today and everyday," Lerner said.

Chief Sidney Hill of the Onondaga Indian Nation and Chief Oren Lyons, Faithkeeper of the Turtle Clan of the Onondaga Nation, took the stage next.

Lyons described Ali as "a free and independent spirit."

"He stood his ground with great courage and conviction," Lyons said.

Later, Rabbi Joe Rapport of Louisville said Ali was "the heart of our city ... and that heart beats still."

After Venerable Utsumi and Sister Denise spoke, Ambassador Attalah Shabazz, the daughter of Malcolm X, stepped up to the podium.

As she spoke, she quoted her father, saying, "For if you love God, you can't love only some of his children. Love is a mighty thing, devotion is a mighty thing, and truth always reigns."

President Barack Obama was unable to make the trip because of his daughter Malia's high school graduation. But White House adviser Valerie Jarrett read a letter from the president at the service in which Obama said Ali helped give him the audacity to think he could one day be president.

"Muhammad Ali was America. Brash. Defiant. Pioneering. Never tired. Always game to test the odds. He was our most basic freedoms: religion, speech, spirit," Obama said.

Inside the arena, the main stage featured the American and Olympic flags.

Earlier in the afternoon, the Rev. Jesse Jackson, Martin Luther King III, and promoter Don King were spotted entering the center -- just two of many who came to pay their respect to The Greatest.

An overflow area was set up in the Belvedere area downtown with big screens set up for viewing.

PHOTOS: Muhammad Ali's memorial service

The Associated Press contributed to this report.