ABC News' Linzie Janis reports:

An Oklahoma woman who says she encountered God in a nine-minute brush with death describes her communication with the higher power as "effortless."

"I was standing in the most beautiful tunnel of light," Crystal McVea told ABC News. "There were no words. It was just effortless communication between us."

McVea, 36, says she encountered God nearly four years ago, in December 2009, while being treated for pancreatitis. After being accidentally overdosed on pain medication, McVea's heart stopped beating and doctors struggled to revive her for nine minutes.

McVea, a mother of four, says she at first declined God's offer to return to her body but then heard a calling that brought her back to life.

"I heard my mother scream my name," said McVea. "And I stopped and I said, 'Can I tell her I'm okay?,' and He said, 'The choice is up to you.'"

"I didn't want to come back to my life but I still turned around," she said. "I was right back into my body."

McVea documented her experience in her book, " Waking Up in Heaven." In the book she explains why she was surprised that she, of all people, encountered an experience with God.

McVea told ABC News her near-death experience shattered her lingering doubts about her faith.

"I was sexually abused for many years of life," she said. "And it wasn't that I didn't believe in God, it was that I questioned his existence my whole life…'What kind of God could allow this abuse to happen?'"

"All of that fell off in the presence of God," McVea said.