'O God' in the Bible

And Solomon said unto God, Thou hast shewed great mercy unto David my father, and hast made me to reign in his stead.

And said, O LORD God of Israel, there is no God like thee in the heaven, nor in the earth; which keepest covenant, and shewest mercy unto thy servants, that walk before thee with all their hearts:

Have ye not cast out the priests of the LORD, the sons of Aaron, and the Levites, and have made you priests after the manner of the nations of other lands? so that whosoever cometh 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 on this manner, neither yet believe him: for no god of any nation or kingdom was able to deliver his people out of mine hand, and out of the hand of my fathers: how much less shall your God deliver you out of mine hand?