'O God' in the Bible

For from you sounded out the word of the Lord, not in Macedonia and in Achaia only: but your faith also which ye have unto God, spread herself abroad in all quarters, so greatly that it needeth not us to speak anything at all:

for they themselves show of you what manner of entering in we had unto you, and how ye turned to God from images for to serve the living and true God,

For what thanks can we recompense to God again for you, over all the joy that we joy for your sakes before our God,