Why don't those that deny the authenticity of the Bible Write one and show everyone how easy it is to do?

It's been done already. Repeatedly. Ever heard of the Jefferson Bible?

One might think that you never heard of Joseph Smith or L. Ron Hubbard.

It is easier to claim that one of the prophets asked Yahweh to make the shadows move the other way, and the shadows DID move the other way, if one is a bronze-age bard, making up a story, and is unaware of the rotation of the Earth, and the consequential motion of shadows.

But, once the fact gets established that Yahweh would have had to suddenly backspin a planet going about 1,000 MPH at the equator, and that the sudden backspin would have caused enormous, permanent, and identifiable geologic upheaval, visible for centuries, it becomes obvious that the God (if any) which got the world spinning, is not the same God (if any) who inspired the writer to tell the story that way.

Same deal with John of Patmos claiming that the stars are actually so small that 1/3 of them will be "cast down to Earth".

GOd knows that stars are big. People who claim God told them to write stuff, had better write accurate stuff, based on what God knows, not on what appear to be tiny twinkling lights.

I've written books. The bible is nothing more than a collection of books. Most of the attributed authors have only one book of the bible attributed to them, so it's a life's work. Some parts are just transcriptions of letters (Corinthians). Some are just collections of saying and wisdom (Proverbs). Nothing so difficult to do if one simply has the time to devote to it.

Oh you happy mormon you. . . that is just plain silly. Go back to your Book of Mormon and read what it says in Moroni 10:4-5. It doesn't matter what others tell you, as long as you have your testimony it doesn't matter what people say about your beliefs. Practice what so many of your people preach and don't rely on the wisdom of the world to make you convince yourself that what you believe is true. . . just a bit of advice for you.

In the Beginning, There was The Barney. And The Barney said "Let Us Sing a Happy Song". And The Barney looked about and saw that there was No Us, only Barney and was Sad.

That is hysterically funny coming from a mormon!

Compare the bible and Christian beliefs with the Mormon book and beliefs and it is as plain as day that Mormons only claim to be Christian because they are afraid to stand up as an entirely separate religion!

This would depend on the denier's storytelling, history, and writing skills. Just try not to end up like Snoopy when he writes his manuscripts. Hopefully, they'll make something better than Twilight.

Are you aware of the fact that the Bible was written by hundreds of people over thousands of years?

You mean like, Lord of the Rings? yeah, I probably couldn't write something like that.

All books of fiction are authentic ...

But please, could you please just provide a bone, a tooth, a grave showing Jesus actually was around? For a guy so important, his whereabouts are sure questionable.