Thank you for the question on what is so special about the Bible.
For one’s consideration of what is so special about the Bible:
A. The Bible is God’s revelation about his relationship to his created world, not man reaching out to God.
B. The Bible is God’s record of how a person can have a restored relationship with the Creator God.
C. The Bible is God’s future restoration of the fallen world to its glory and beauty.
SUMMARY: The Bible is God’s book of his relationship to the world.
For further insight and discussion:
https://www.quora.com/Can-anyone-enlighten-me-on-what-is-believed-to-be-so-special-about-the-Bible