Do you think Christianity is a really good made up book.

It's aight. I think Christianity really shines when it comes to the art that was based on the stories. Churches, statues, paintings, that's the really good stuff.

No, there are too many historically verified prophesies which were fulfilled. The Messiah was prophesized in several places in Isaiah especially, with amazing detail about his birth and death. There's a 700 year gap between that prophecy and Jesus crucifixion and resurrection and also extra biblical historical sources as well as multiple fragments of original Bible manuscripts that outweigh any other book from antiquity.

I think that is very possible

No it's not made up