WATCH: Cancer-Stricken NFL Legend Jim Kelly's Powerful ESPY Speech

"I will never give up. I will keep fighting til the end. Get up, you'll be alright."

Jim Kelly has been through the wringer: vicious bouts with cancer that just won't go away and the devastating loss of a young son. And, still, he has not lost his faith.

The cancer-stricken NFL Hall of Famer gave a powerful speech after accepting the iconic Jimmy V Award for Perseverance at the 2018 ESPYs in Los Angeles on Wednesday night. The legendary athlete, devoted family man, and philanthropist urged others to dedicate themselves to "make a difference today for someone who is fighting for their tomorrow."

As noted by Sports Illustrated, Kelly — who tragically lost his son 8-year-old son Hunter in 2005 — has had a fierce battle with cancer. In 2013, he was first diagnosed with squamous cell carcinoma in his upper jaw, had surgery to remove the cancer and reconstruct his jaw and was subsequently declared cancer-free. But the cancer was discovered just a year later. Kelly underwent chemotherapy and radiation treatment and had a major 12-hour surgery on his jaw to be declared cancer-free for the second time, though, sadly, that diagnosis didn't last long; in March, his cancer had reemerged.

Choked up, Kelly started his speech with mention of his late son. "So many times I dreamt and continue to dream about my son Hunter and what he's meant in my life," he said. "And it will never stop."

Hunter, 8, lost his battle with Krabbe Disease, a fatal nervous system disease for which there is no cure, in August of 2005. In 1997, the year Hunter was born, Kelly and his wife Jill established a non-profit Buffalo-based organization called Hunter's Hope Foundation, which has raised millions of dollars for Leukodystrophy research, family care, education, and awareness.

Kelly told the audience that his life's "four 'f'" mantra of "fun, family, friends, and fans" has been changed since facing such tough challenges in his life. The "fun," he said, has been replaced with "faith."

"My faith in the good Lord, that he has plans; he has plans for my life. Through my son Hunter, we will make a difference," he said.

The tough athlete thanked loved ones for their support, singling out his two daughters and wife, whom he said are "my heart, you are my soul, you are my everything."

Kelly wrapped up the speech by encouraging his fans to help others. "Make a difference today for someone who is fighting for their tomorrow," he said. "You don't need to be a Russell Wilson, Aaron Rodgers to make a difference; every single person in this room can be a difference-maker."

"What you say to them, the smile on your face, that can be the difference," he said. "Always, always persevere."

"I love all of you, God bless. And may the good Lord continue to bless you," Kelly concluded.

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