Now can we please look at this with discernment.
"There are those who believe that science will eventually explain everything—including our enduring belief in heaven. The thesis here is very simple: heaven is not a real place, or even a process or a supernatural event. It's something that happens in your brain as you die."
So what they are really saying is that there really is a heaven, and that is why humans believe in it (and have believed in it for thousands of years), but this author wants to change the definition of heaven to some explanation that limits it or alters it to something non-spiritual. In essence, he is giving credence to the belief, but he wants to remove the spiritual content with a "thesis" of his. On what authority rests his "thesis" ? And whose thesis is it?
Now the key sentence:
"Science cannot definitively proof or disprove Chris's theory, but some scientists are willing to take guesses"
First, we see that this is the "theory" of his friend "Chris," based on some anecdotal encounter with his father who had a "vision." What is scientific about this? Please point me to the science because I don't see any.
This is called interpretation. This is called philosophy. Call it anything you like, but do not insult my intelligence and call this science and then "blame" science for being on some crusade against religion. This author (and his friend Chris) may be on a crusade against religion (or he simply doesn't believe in it), but "science" is not.
The author has admitted he is making a guess. He is taking the research and the facts uncovered about "near death experiences" and he is forming a philosophy out of it, which says that near death experience is what motivates the human belief in heaven. On what is this guess based? Like all guesses, it includes projection, conjecture, wishful thinking, denial of other possibilities - even more plausible ones, etc. The sentence I cited above is worth quoting again.
"Science cannot definitively proof or disprove Chris's theory, but some scientists are willing to take guesses"
Once one is "guessing," we have been removed from the discipline of science, and we have entered the quasi-"discipline" of science fiction. He also gives credence to the idea which I constantly stress regarding this topic. Science is a discipline that investigates the physical world and uncovers facts about the physical world. Science is not capable of explaining the "supernatural" because supernatural is not within the realm of science - science only has the tools to investigate the physical world, and this defines science. By saying science cannot definitively prove or disprove his idea, the author is admitting to this basic reality. Yet he tries to promote his idea anyway. Well, anyone can get on a soapbox and say anything. That doesn't mean I have to believe it. And certainly not when I have been given the truth on Mount Sinai.