'O God' in the Bible

But the angel of the Lord said to Elijah the Tishbite, “Go and meet the messengers of the king of Samaria and ask them, ‘Is it because there is no God in Israel that you are going to inquire of Baal-zebub, the god of Ekron?’

They replied, “A man came to meet us and said, ‘Go back to the king who sent you and declare to him: This is what the Lord says: Is it because there is no God in Israel that you’re sending these men to inquire of Baal-zebub, the god of Ekron? Therefore, you will not get up from your sickbed—you will certainly die.’”

Then Elijah said to King Ahaziah, “This is what the Lord says: ‘Because you have sent messengers to inquire of Baal-zebub, the god of Ekron—is it because there is no God in Israel for you to inquire of His will?—you will not get up from your sickbed; you will certainly die.’”

Then Naaman and his whole company went back to the man of God, stood before him, and declared, “I know there’s no God in the whole world except in Israel. Therefore, please accept a gift from your servant.”