One unifying religion for all the people. The Book is, without a doubt, a revelation from the Lord of the Universe.
The Final Testament comes with built-in physical evidence that it is God's message to you; it is mathematically composed beyond human capability. This proves that God is the Truth, and that He revives the dead, and that He is Omnipotent.
This book consolidates all the messages delivered by all of God's messengers into one global message -
"Total submission to God - worshiping God and devoting the worship absolutely to Him ALONE!"