Each of the various philosophical arguments for God's existence, such as the argument from design (the complex design proves an intelligent Designer), and the argument for first cause (that all effects must be ultimately traced to an intelligence that was the first cause of all effects), is conclusive enough, but collectively, all the arguments are absolutely overwhelming.
The same logic applies to the Bible. Each of the above individual arguments is enough, but collectively they overwhelmingly reveal that the Bible is clearly the authoritative Word of God, totally reliable and true.
The information presented in this book is so revolutionary and radical, it is absolutely necessary that its authoritative basis, the Bible, be constantly clear in the mind of the reader. Otherwise, you could not believe it and receive God's promises.
Believe it.
Suggested reading:
Evidence That Demands a Verdict, Josh McDowell (Nashville: Thomas Nelson Publishers, 1999) (also, New Evidence That Demands a Verdict, 1999).
Why I Preach the Bible is Literally True, W.A. Criswell (Nashville: BroadmanPress, 1969).