Evangelist Billy Graham has said that sometimes, God gives people a glimpse of Heaven's glory to remind us that eternity is real - and that Christ is waiting to welcome us to our eternal home.

The 99-year-old founder of the Billy Graham Evangelistic Association recently responded to a question sent to him by a reader: "My uncle says my aunt had a glimpse of Heaven just before she died. How does he know? Maybe she was just having a hallucination. I admit I'm a bit skeptical, although my aunt was a very spiritual person who read her Bible every day," the reader said.

Graham said although it is unusual, God does sometimes gives people a glimpse of Heaven just before they die. He used the first Christian martyr, Stephen, as an example.

"As the stones thrown by his enemies rained down upon him, Stephen...'looked up to heaven and saw the glory of God, and Jesus standing at the right hand of God' (Acts 7:55)," he said.

Why does this happen? Graham dismissed those who claim such visions are hallucinations or chemical reactions in the brain, saying, "I am convinced it is instead a God-given glimpse into eternity."

"Through it, God is reminding those who are present-and us as well-that eternity is real, and Christ is waiting to welcome us into Heaven," he explained. "He alone is our hope, because by His death on the cross He paid the price for our sins, and by His resurrection from the dead He conquered death and Hell and Satan."

Still, it's important to not be misled by stories of visions or "tunnels of light" or other experiences, the evangelist warned.

"Sometimes Satan tries to imitate God's work, deceiving people into thinking they don't need to commit their lives to Christ in order to be saved," he said. "Remember: Satan 'is a liar and the father of lies' (John 8:44)."

In recent years, a number of books and movies have emerged featuring people who claim to have visited heaven during near-death experiences.

In 2015, Alex Malarkey, who, as a 6-year-old in 2004, suffered a horrific accident and supposedly saw heaven while in a coma, made headlines after recanting his story, which was the subject of the wildly popular book The Boy Who Came Back from Heaven.

"I did not die. I did not go to Heaven," he said.

"I said I went to heaven because I thought it would get me attention. When I made the claims that I did, I had never read the Bible. People have profited from lies, and continue to. They should read the Bible, which is enough. The Bible is the only source of truth. Anything written by man cannot be infallible.

Concerns over stories of "Heaven tourism" prompted members of the Southern Baptist Convention to pass a resolution reaffirming "the sufficiency of biblical revelation over subjective experiential explanations to guide one's understanding of the truth about heaven and hell."

However, Todd Burpo, whose book Heaven is for Real recounts how his son visited Heaven, met Jesus, saw angels, and watched Mary kneel before the throne of God after slipping from consciousness while having his appendix removed in an emergency operation, The Gospel Herald that his story is absolutely true - even though it "will always have skeptics."

"People have their right to make their own decision, God gave us all that right. But we know what we saw and heard and our experience," he said. "Praise God; we never thought our story would help and encourage so many people, but God has given us the chance to do that, and and as long as He keeps giving us the chance to keep encouraging people and point them to Him, we're just going to keep right down that road."

Christy Beam, whose book Miracles from Heaven documents how her daughter, Annabel, visited Heaven and met Jesus after a devastating fall, also shared how she reacts to those who question the story's authenticity.  

"My favorite response to that question is Annabel's," she told GH. "She says, 'I don't say anything to those who criticize and don't believe. What I do say is, this is my story and it is real and I am living proof of a miracle. I'm not going to shove it down your throat, but if you allow it to, it could change your life, it could help you to have a relationship with Jesus if you don't have one, and it could strengthen who He is for your relationship if you allow it to. But if you don't that's fine, but it is my story.' I feel like that's the best response in the world from a 12 year old."