Deciphering whether if the Bible is "true" or not heavily depends on which truth claims you are referring to. For example, if I were to write an email to my parents about my thoughts on Star Wars, but I quoted some of its lines wrong ("Use the power, Luke"), is this review of the movie true?
The information about the movie is true, the quote is slightly (but not completely) true, and my opinions are true to my heart. Since my parents are not aware of any of the cultures and terminologies surrounding the movie, I will need to carefully substitute strange concepts with words that are more familiar to them. They would not know what the "force" is, so I would need to use the word, "power."
Now, with the information that I just revealed, it is understandable why I used the word "power" instead of "force."
The Bible was written to ancient Hebrew people. Their understanding of the earth was different than ours. Did you know that the ancient Hebrews believed that we lived inside of a dome with water above and below them? They believed that God lived somewhere above, and that dead people went somewhere below (which makes sense, since when we die, our bodies return to the ground, and the opposite of down is up). The Bible was written to a specific audience, and we are not it.
Here's the key to understanding the Bible: God, instead of correcting their worldview, decided to teach them the truth about Himself and humanity utilizing their words and props.
So, is the Bible true? Regarding the subject that the Bible is attempting to answer, yes. Is the Bible true in discerning scientific fact? It depends on how advanced their civilization was.
Now that we know that the Bible cannot be the source material for science, what can be said about its historical reliability?
A few years ago, I came across an acrostic that covered four tests that proved the validity of the Bible: SPAM.
S - Secular Evidence. There are written sources outside the Bible that confirm the events of the Scriptures. For example, a historian named Flavius Josephus records about a man named Jesus who performed miracles and was killed on a cross.
P - Prophecies. The Bible dares to predict the future (although that is not what prophecy means entirely). As far as the prophecies that have already come to pass, they are 100% accurate.
A - Archaeological Evidence. The locations and events recorded in the Bible have not been disproven by archaeological findings. For years, people thought King David was a fictional character. However, in recent digs, coins were discovered with David's engraving. Same goes for Bethlehem - people thought the birthplace of Jesus was mythical. However, in the past few decades, the city has been dug up.
M - Manuscript Consistency. Even if the Bible is found to be true, there is a chance that the version of the Bible we have in our hands today is erroneous due to human error. This was the biggest argument against the validity of the Bible for a long time. However, the discovery of the Dead Sea Scrolls in 1947 (dated to be at least 2000 years old - the oldest manuscripts in existence) proved that there is little to no discrepancies between the versions.
The Bible is a collection of 66 books, written by 40+ authors (most did not know each other), in three continents (and even more cultures), in a span of 1500 years, originally written in three languages. Yet, the themes are consistent. What other collection of books can say that?