'O God' in the Bible

but concerning the Son, "Your throne, O God, [is] {forever and ever}, and the scepter of righteous [is the] scepter of your kingdom.

Therefore he was obligated to be made like his brothers in all [respects], in order that he could become a merciful and faithful high priest in the things relating to God, in order to make atonement for the sins of the people.

For every high priest taken from among men is appointed on behalf of people in the things relating to God, in order that he can offer both gifts and sacrifices on behalf of sins,

(for the law [made] nothing perfect), but on the other hand [there is] the introduction of a better hope through which we draw near to God.

Therefore also he is able to save completely those who draw near to God through him, [because he] always lives in order to intercede on their behalf.

how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, cleanse our consciences from dead works to serve [the] living God?

Then I said, 'Behold, I have come-- in the roll of the book it is written about me-- to do your will, O God.'

By faith Abel offered to God a greater sacrifice than Cain, by which he was approved that he was righteous, [because] God approved [him] for his gifts, and through it he still speaks, [although he] is dead.

By faith Enoch was taken up, so that he did not experience death, and he was not found, because God took him up. For before his removal, he had been approved {as having been pleasing} to God.

and assembly of the firstborn who are enrolled in heaven, and to God the judge of all, and to the spirits of righteous [people] made perfect,

Therefore through him let us offer up a sacrifice of praise {continually} to God, that is, the fruit of lips that confess his name.