'O God' in the Bible

We give thanks to God always for all of you, making mention of you in our prayers;

For they themselves report about us what kind of a reception we had with you, and how you turned to God from idols to serve a living and true God,

who both killed the Lord Jesus and the prophets, and drove us out. They are not pleasing to God, but hostile to all men,

For what thanks can we render to God for you in return for all the joy with which we rejoice before our God on your account,

For if we believe that Jesus died and rose again, even so God will bring with Him those who have fallen asleep in Jesus.