How do we know that the doctrine of scripture being God-breathed is true?

The doctrine that all scripture is God-breathed is backed by the authority of scripture itself, particularly in 2 Timothy 3:16-17. This passage asserts that the writings are not simply human thoughts but are divinely inspired by God. The Holy Spirit moved upon the authors of scripture, ensuring that what they wrote was exactly as He intended. Therefore, the reliability and truth of scripture stem from its divine origin rather than human effort, making it a trustworthy source for guidance in salvation and righteous living.