Epistle To The Hebrews Book: Gospels Which Were Not Included In The Bible

I wanted to know more about the conception of Christ, Well I found it! Most of all I wanted to know why according to which Christian Denomination you belonged to had different Bibles with different books, some Bibles had as little as 24 books while others ranged all the way out to 91 books! I was no longer interested in hearing others' opinions I wanted to read, study for myself, and form my own opinion on each subjective book. I wanted to see the truth at the back of it.