"I talk to God every single day, and I say, 'God, my life is in your hands, and I trust you with me,"' she told CNN's Larry King Thursday.
Messner, 65, wearing heavy makeup and a matching red blouse and jacket, appeared emaciated and spoke in a raspy voice. She said she weighs only 65 pounds.
"All I eat is chicken soup and rice pudding," said Messner, who, in a message to fans and followers on her website, asks for prayers that she'll be able to keep her food down - and says past prayers have helped, since she's been able to gain five pounds.
Messner was diagnosed with colon cancer in 1996 and announced in 2004 that the disease had spread to her lungs. Doctors have since stopped treating the disease, she has said.
Asked Thursday night if she had a message for viewers, Messner said: "I genuinely love you, and I genuinely care. And I genuinely want to see you in heaven someday."
The minister and author is not forgotten by those she has inspired; some 228 pages of messages and prayers from well-wishers are posted on her website.
Messner is best known for, with her then-husband Jim Bakker, having built the PTL ("Praise The Lord") televangelism empire - a multimillion dollar operation that at one point included a television network and a theme park.
Messner divorced Bakker in 1992, while he was serving a sentence for financial fraud.