Why do some people say heaven is real when they have never been there before?

Well I have never been to outer space or France before but I know it exists because other living humans have gone there. There are pictures and I have heard the 1960s space land by Neil Armstrong was shown on live television.

No living human has ever gone to heaven before.

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Another way I also know France exists is because I can also go online and book a plane ticket to go there.
There is no plane ticket to heaven.

I currently don’t own a telescope but I know I can also buy a telescope online which would give me the ability to see into outer space.
Telescopes cannot see heaven.
Why do some people say heaven is real when they have never been there before?
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