To convince me that a book is written by God, it will have to contain information only God could know, but which can still be verifiable by me. This is likely impossible.
For example:
A list of all major global future events of types that are not possible for anyone but godGod to influence, like a complete list of all volcanovolcanic eruptions and earthquakes for several years, with magnitudes and death tolls, is not enough. These events are not possible to influence, but a book from the future could record them, so this does not exclude time travelers.
A detailed list of local weather changes everywhere I go for months would also be impossible to predict, and to control. Temperature to the centigrade, exactly when rain stops and starts, and thunder claps, recorded to the second. That excludes everything except somebody who secretly follows me around for months to record this, and then sends the book back from the future.
Let usLet's say that the book included things only I could know, such as private information about me and my thoughts. But that still doesn't exclude a cooperation between time travelers and a future me, and this is where it gets tricky.
LetsLet's say somebody has small technological insects that monitor me, and record everything I do, and everything that happens, including major earth quakesearthquakes and my local weather for years. They then compile a book of this, and cooperate with a future me that adds information only a future me would know and sends that book back. I do not see any way to put information in the book that a combination of a future me and these time hitechhigh-tech travelers would not know.
Hence, I can not find anything to put in a book that only God could know that would still be verifiable by me.