'O God' in the Bible

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

They said to him, “A man came up to meet us and said to us, ‘Go, return to the king who sent you and say to him, “Thus says the Lord, ‘Is it because there is no God in Israel that you are sending to inquire of Baal-zebub, the god of Ekron? Therefore you shall not come down from the bed where you have gone up, but shall surely die.’”’”

Then he said to him, “Thus says the Lord, ‘Because you have sent messengers to inquire of Baal-zebub, the god of Ekron—is it because there is no God in Israel to inquire of His word?—therefore you shall not come down from the bed where you have gone up, but shall surely die.’”

When he returned to the man of God with all his company, and came and stood before him, he said, “Behold now, I know that there is no God in all the earth, but in Israel; so please take a present from your servant now.”