Why the bible?
The Bible (also called Scripture) is an exceptional book. What makes it so special and extraordinary?
It is the most read, most printed, the most translated and most widely distributed book in the world.
There are total translations in 469 languages and partial translations in over 2527 languages.
Every year, 30 to 40 translations are added. The Bible is not just a single book, but a small library with 66 individual books. 
It is the most amazing book that people know. No other book was written by more than 40 writers from different periods and different social classes. No other book was written in a period of around 1600 years. The Bible is unique in its origin, tradition, distribution and actuality.
But it is also a book that is repeatedly attacked, fought and criticized. But whoever traces the history and origins of the Bible will conclude that God has watched over his word for thousands of years. Thousands of manuscripts from the Old and New Testaments confirm the unique source of the Bible. So there is no reason to doubt the Bible and its content. 
The Old Testament was in the period from about 1400 - about 400 BC. Written in Hebrew and Aramaic. The New Testament was written in Greek between AD 30 and around 95.
The Old Testament (First Testament) begins with the creation of the world. It describes the history of the people of Israel, contains a lyrical part and prophetic writings.
The New Testament (Second Testament) describes the life of Jesus in four gospels (books) and the life of the first Christians. It also contains 21 letters to Christian communities and the book “Revelation”, which describes heaven and the end of the world. 
The Gospels report in the New Testament about the work, life, death and resurrection of Jesus. If you compare all four Gospels, you will find that there are certain differences in the stories and reports. Why? At that time, the eyewitnesses experienced the event from different perspectives. These small differences serve as a supplement and confirm the credibility of the reports. The four gospels are not identical because they were held by four different people at different times. These reports complement each other and complete the overall picture of Jesus. It is certain that the Gospels agree on all essential points and differ only in details. This makes the reports even more credible. No judge would rely on the witnesses, who all tell exactly the same story with the same words. It would be clear: they must have agreed and make themselves unreliable by their exact story. In addition, problems and contradictions are not left out and this fact also makes the Bible credible.
If you look more closely, you can see that the whole Bible tells a unified and clear message. That is the story of God with people. Another proof that the Bible is God's Word is the many prophecies. Many of these predictions have already been fulfilled, others will become reality today and in the future. One could say: "It was a coincidence". But that is not possible because all biblical fulfillments have been historically documented and confirmed. The Bible's 3268 predictions are the greatest proofs of truth of Christian faith and the Bible as a book of truth.
So there is no reason to doubt the correctness of biblical statements and the testimonies of biblical writers.
However, the Bible is questioned by many Christians and theologians because many things are “scientifically unsustainable” today and therefore “unbelievable”. Only when you remove the human elements would you have the true Word of God. This reasoning is based on a human judgment and evaluation of the Bible, which cannot understand divine inspiration. The following statement from the Bible contrasts with this:
“The Word of God is alive and effective. It is sharper than the sharpest sword and penetrates our innermost thoughts and desires. It reveals who we really are and reveals our hearts to God. Nothing in all of creation is hidden from him. Everything is naked and only before the eyes of God, to whom we have to be accountable for everything. ”Hebrews 4, 12-13 (New Life Translation)
No one is able to formulate prophecies that are fulfilled without exception. The true author of the Bible is Almighty God Himself, so the whole Bible is true.
The writers of the Bible were people who received the message from God and wrote it under the guidance of his Holy Spirit. The word inspiration is used for this, which means "breath". It is said that all of Scripture was entered by God's Spirit himself so that the Bible would contain what God wanted people to write down. Rather, the Word of God is a letter and a way of life for us humans. We really find the answers to the important questions of life and belief in the Bible, God's Word, which is true and inspired by God's Spirit.
“Because everything that is in the Scripture is input from God's Spirit, and the use of the Scripture is correspondingly great: it teaches in the truth, reveals guilt, leads on the right path and educates to a life according to God's will. “2 Timothy 3:16
Since the Word of God was inspired by the Holy Spirit, the Holy Spirit is the key to understanding the Bible. In personal heart prayer, reconciliation with God and fulfillment with His Holy Spirit is possible. When a person turns to Jesus wholeheartedly, the veil is removed from his eyes and that person realizes the truth about God and his word. But this heart decision is essential to understand God's instructions, promises and plans on the spiritual level.
There are Bible translations that are as close as possible to the original Hebrew text in the Old Testament and to the original Greek text in the New Testament. Try to use only the Bible translations that are based on the original text and contain no theological interpretations.
Sources:  Hinrichs, Miriam: Interessante Fakten zum Buch der Bücher: https://www.jesus.ch/themen/glaube/bibel/197650-interessante_fakten_zum_buch_der_buecher.html, 01.05.2020
 Drüecke, Remmers: Die Bibel-Ihre Geschichte und Überlieferung. 8.Auflage 2015, CSV Verlag.
 Vgl. Quelle 1