'Someone' in the Bible

It is actually reported that there is immorality among you, and immorality of such a kind as does not exist even among the Gentiles, that someone has his father’s wife.

For if someone sees you, who have knowledge, dining in an idol’s temple, will not his conscience, if he is weak, be strengthened to eat things sacrificed to idols?

But someone will say, “How are the dead raised? And with what kind of body do they come?”