'O God' in the Bible

I am thankful to God, whom I serve from my forefathers with pure conscience, how unceasingly I have the remembrance of thee in my supplications night and day,

Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.

Leave worldly, empty phrases alone, for they lead people deeper and deeper into godlessness,

they will be treacherous, reckless and conceited, preferring pleasure to God ??5 for though they keep up a form of religion, they will have nothing to do with it as a force. Avoid all such.

All Scripture is God-breathed [given by divine inspiration] and is profitable for instruction, for conviction [of sin], for correction [of error and restoration to obedience], for training in righteousness [learning to live in conformity to God’s will, both publicly and privately—behaving honorably with personal integrity and moral courage];

that the person dedicated to God may be capable and equipped for every good work.