Zoroaster, also known as Zarathustra or Zartosht, was the prophet of the Zoroastrian religion. It is now thought that he lived in eastern Iran or in central Asia around 1000 BC. The Gathas are hymns held by believers to have been written by Zoroaster.
The translation used here is by Dinshaw Jamshedji Irani. 
- Unto Thee, O Lord, the Soul of Creation cried:
"For whom didst Thou create me, and who so fashioned me?
Feuds and fury, violence and the insolence of might have oppressed me;
None have I to protect me save Thee;
Command for me then the blessings of a settled, peaceful life."
- Ahunuvaiti Gatha; Yasna 29, 1.
- Thus to the Lord doth Asha, the Truth, reply:
"No guide is known who can shelter the world from woe,
None who knows what moves and works Thy lofty plans."
- Ahunuvaiti Gatha; Yasna 29, 3.
- Hearken with your ears to these best counsels,
Reflect upon them with illumined judgment.
Let each one choose his creed with that freedom of choice each must have at great events.
- Ahunuvaiti Gatha; Yasna 30, 2.
- In the beginning there were two primal spirits,
Twins spontaneously active,
These are the Good and the Evil, in thought, and in word, and in deed.
- Ahunuvaiti Gatha; Yasna 30, 3.
- For a thinking man is where Wisdom is at home.
- Ahunuvaiti Gatha; Yasna 30, 9.
- By Thy perfect Intelligence, O Mazda
Thou didst first create us having bodies and spiritual consciences,
And by Thy Thought gave our selves the power of thought, word, and deed.
Thus leaving us free to choose our faith at our own will.
- Ahunuvaiti Gatha; Yasna 31, 11.
- He who upholds Truth with all the might of his power,
He who upholds Truth the utmost in his word and deed,
He, indeed, is Thy most valued helper, O Mazda Ahura!
- Ahunuvaiti Gatha; Yasna 31, 22.
- He who abhors and shuns the light of the Sun,
He who refuses to behold with respect the living creation of God,
He who leads the good to wickedness,
He who makes the meadows waterless and the pastures desolate,
He who lets fly his weapon against the innocent,
An enemy of my faith, a destroyer of Thy principles is he, O Lord!
- Ahunuvaiti Gatha; Yasna 32, 10.
- A reflective, contented mind is the best possession.
- Ushtavaiti Gatha; Yasna 43, 15.
- The resolute one who moved by the principles of Thy Faith
Extends the prosperity of order to his neighbors
And works the land the evil now hold desolate,
Earns through Righteousness, the Blessed Recompense
Thy Good Mind has promised in Thy Kingdom of Heaven.
- Spenta Mainyu Gatha; Yasna 50, 3.
- A righteous government is of all the most to be wished for,
Bearing of blessing and good fortune in the highest.
Guided by the law of Truth, supported by dedication and zeal,
It blossoms into the Best of Order, a Kingdom of Heaven!
To effect this I shall work now and ever more.
- Vohu-Khshathra Gatha; Yasna 51, 1.
- Satisfaction linked with dishonor or with harm to others is a prison for the seeker.
- Vahishto-Ishti Gatha; Yasna 53, 6.