Why do Christians take the bible to seriously?

I see many Christian will believe everything that was written in the bible. For example, people believe that God was the one who wrote the bible. I believe the bible was inspired by men. People got mad at me and said that god is going to punish me just because I said that. Didn't Adam and Eve had only 3 sons? So how can two man make a baby. Didn't the bible said, It's a sin to ? In the bible says that the Earth is flat. Then scientist proved it's a sphere. People who are stupid to believe that the Earth is only 6000 years old. When there's are bones of dinosaurs and Caveman's who died over millions of years ago. If Adam and Eve were created 6,000 years old and look actually like us, Then how do you explain bones that scientist found that look like different human species that died for over 100 thousand years ago?