'O God' in the Bible

And they were helped against them, and the Hagrites were delivered into their hand, and all that were with them: for they cried to God in the battle, and he heeded their prayer; because they put their trust in him.

And say, Save us, O God of our salvation, and gather us together, and deliver us from the nations, that we may give thanks to your holy name, and glory in your praise.

And yet this was a small thing in your eyes, O God; for you have also spoken of your servant's house for a great while to come, and have regarded me according to the estate of a man of high degree, O LORD God.

And David said unto God, I have sinned greatly, because I have done this thing: but now, I beseech you, take away the iniquity of your servant; for I have done very foolishly.

And David said unto God, Is it not I that commanded the people to be numbered? even I it is that have sinned and done evil indeed; but as for these sheep, what have they done? let your hand, I pray you, O LORD my God, be on me, and on my father's house; but not on your people, that they should be plagued.

And his brethren, men of valor, were two thousand and seven hundred heads of the fathers' houses, whom king David made officials over the Reubenites, the Gadites, and the half tribe of Manasseh, for every matter pertaining to God, and affairs of the king.