Joshua 1:8

This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.

2 Timothy 3:16

All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction  in righteousness: