'O God' in the Bible

And Solomon said unto God, You have shown great mercy unto David my father, and have made me to reign in his stead.

And said, O LORD God of Israel, there is no God like you in the heaven, nor in the earth; who keeps covenant, and shows mercy unto your servants, that walk before you with all their hearts:

Have you not cast out the priests of the LORD, the sons of Aaron, and the Levites, and have made yourselves priests after the manner of the nations of other lands? so that whosoever comes to consecrate himself with a young bullock and seven rams, the same may be a priest of them that are no gods.

Now therefore let not Hezekiah deceive you, nor persuade you in this way, neither yet believe him: for no god of any nation or kingdom was able to deliver his people out of my hand, and out of the hand of my fathers: how much less shall your God deliver you out of my hand?