'One's' in the Bible

He then told them, “Watch out and be on guard against all greed because one’s life is not in the abundance of his possessions.”

saying, 'Teacher, Moses wrote to us, If any one's brother may die, having a wife, and he may die childless -- that his brother may take the wife, and may raise up seed to his brother.

In the resurrection therefore, which one’s wife will she be? For all seven had married her.”