How does heaven look and feel like? Is God at the gate waiting for heaven's newcomers?

People like us who have never ventured yet into the Great Unknown, that moment when life as we know it ceases, would never really know.

But there are many people, those who have had "near death experiences," who have had glimpses of heaven and, yes, hell as well.

So what did they actually see?

Pastor John Burke researched 1,000 of these near death experiences and came up with a new book called "Imagine Heaven," CBN News reported.

Burke, a New York Times best-selling author, said his research provides new evidence of the biblical account of eternity.

He said the people who have had near death experiences told him that they met a "man of light."

Based from their descriptions of what they saw, Burke said the "man of light" can only be God. Those who believe in Jesus said they recognised the man as Jesus, he said.

The author said each of the persons he talked to had extraordinary sensation of being completely known and loved in the presence of this "man of light."

Burke said one of the persons he talked to was blind before he had a near-death experience. But the man said he was able to see clearly for the first time and saw heaven as "a bright world where light was emanating from everything," just like the description in the Holy Bible.

While some people experienced heaven, others admitted that they were given a glimpse of hell, which was apparently too frightening for them to put into words.

The author said the narratives of those who have experienced the afterlife have convinced even die-hard sceptics that indeed there is heaven and hell after death.

One sceptical doctor, for instance, found out from one of his patients remarkable details of what went inside the hospital's operating room after he passed out.

Burke's research was not the first to explore the afterlife. In 2014, scientists at Southampton University found evidence that awareness can continue for at least several minutes after clinical death which was previously thought impossible, according to The Telegraph.

The scientists had spent four years examining more than 2,000 people who suffered cardiac arrests at 15 hospitals in the U.K., U.S. and Austria.

They found that nearly 40 percent of people who survived described some kind of "awareness" at the time when they were declared clinically dead before their hearts started pumping blood again.

One man even recalled leaving his body completely and watching doctors as they tried to resuscitate him.

"We know the brain can't function when the heart has stopped beating," said Dr. Sam Parnia, a former research fellow at Southampton University, now at the State University of New York, who led the study.

"But in this case, conscious awareness appears to have continued for up to three minutes into the period when the heart wasn't beating, even though the brain typically shuts down within 20-30 seconds after the heart has stopped.

"The man described everything that had happened in the room, but importantly, he heard two bleeps from a machine that makes a noise at three minute intervals. So we could time how long the experienced lasted for.

"He seemed very credible and everything that he said had happened to him had actually happened."