The statement that best describes the beliefs of Zoroastrianism is:
Good and evil constantly struggle for control of the universe.
Zoroastrianism teaches that the universe is in a constant struggle between the forces of good (represented by Ahura Mazda) and the forces of evil (represented by Angra Mainyu or Ahriman). This dualistic view emphasizes the roles of individuals in choosing between good and evil, highlighting the importance of human agency in this cosmic battle.