The Charlie's Angels star was told by doctors she had anal cancer in 2006 and underwent chemotherapy in a bid to beat it.
She recently learned the disease had spread to her liver and is set to undergo one last course of treatment.
But the 62-year-old is refusing to give up hope -- and is praying that her faith in God will keep her alive.
In documentary footage chronicling the actress' cancer fight, she says, "I want to stay alive. So I say to God, because it is, after all, in his hands, 'It is seriously time for a miracle'."
And the star's best friend Alana Stewart, who shot the footage for the documentary, has revealed the extent of Fawcett's bravery during her battle.
Stewart tells ETonline.com, "She hasn't cried a lot. There's times during these last two years where she has broken down and cried, and then she'll say, 'I'm sorry, I'm sorry -- I don't mean to be a baby.' And I've said, 'Baby, are you kidding? I couldn't go through one-tenth of what you've gone through.' And I've said to her, 'You're the most amazing, the strongest person I've ever known,' and she is."
The video diary detailing Fawcett's fight against the deadly disease is due to air on Friday.
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