'O God' in the Bible

Glory to God in the highest, And on earth peace among men in whom he is well pleased.

And coming up at that very hour she gave thanks unto God, and spake of him to all them that were looking for the redemption of Jerusalem.

And it came to pass in these days, that he went out into the mountain to pray; and he continued all night in prayer to God.

Were there none found that returned to give glory to God, save this stranger?

And immediately he received his sight, and followed him, glorifying God: and all the people, when they saw it, gave praise unto God.

And he said unto them, Then render unto Caesar the things that are Caesar's, and unto God the things that are God's.