'O God' in the Bible

Solomon said to God, "You have shown great loving kindness to David my father, and have made me king in his place.

and he said, "Yahweh, the God of Israel, there is no God like you, in heaven, or on earth; you who keep covenant and loving kindness with your servants, who walk before you with all their heart;

Haven't you driven out the priests of Yahweh, the sons of Aaron, and the Levites, and made priests for yourselves after the ways of the peoples of [other] lands? so that whoever comes to consecrate himself with a young bull and seven rams, the same may be a priest of [those who are] no gods.

Now therefore don't let Hezekiah deceive you, nor persuade you in this way, neither 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 will your God deliver you out of my hand?"