You should never doubt that the word of God is holy inspired. If it were not, then why would a mighty God allow the falsehoods of His divinity to exist? Or why would the correctness of the book hold up over time at a greater rate then anything else written during its time? Only divine intervention can explain.
For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit.
2 Peter 1:21 ESV