The Zoroastrian concept of divine order and truth is called Asha. The Avestan term aṣ̌a combines ideas of truth, righteousness, cosmic order, and the proper functioning of reality, so no single English word captures its full range.
Asha is central to Zoroastrian theology and is opposed by Druj, meaning falsehood, deceit, or disorder. Humans participate in this cosmic struggle through their choices, especially by following the ethical ideal of good thoughts, good words, and good deeds.
Asha is also personified as Asha Vahishta, usually translated “Best Truth” or “Best Righteousness.” Asha Vahishta is one of the Amesha Spentas, the major divine beings associated with Ahura Mazda. The concept appears throughout the Avesta and is especially important in the Gathas, the hymns traditionally attributed to Zoroaster.
A common mix-up is Vohu Manah, or “Good Mind,” which is another Amesha Spenta rather than the name for divine order itself. Khvarenah instead refers to royal or divine glory, while Druj is Asha’s opposing principle.