The Holy Book is Bible. The Bible is sacred canon for Christian people. It is the source of all that is necessary and sufficient unto salvation. The Bible is to be received through the Holy Spirit as the true rule and guide for faith and practice. Christian people properly read Scripture within the believing community, informed by the tradition of that community.
Christian people interpret individual texts in light of their place in the Bible as a whole.
The Bible containNew Testament and Old Testament. The Old Testament contains the history of how the world was created, how people started to believe in God, and God promised to send a Savior to save people from their sins. The New Testament contains about Jesus's life, and his speech about how to be a Chritian. Christian people believe in Jesus Christ, truly man, in whom the divine and human natures are perfectly and inseparably united. He is the eternal Word made flesh.