Ferdowsi has not judged one dimensionally and one sidedly. On the one hand, a reflection of the Zoroastrian beliefs about the role of struggle in human life has been reflected in Shahnameh. The writer rationalistically believes that human beings can make their own faith. The rationalism of Ferdowsi could be observed in Zal story. On the other hand, Ferdowsi believes in faith and destiny. Ferdowsi believes that human beings have no choice from this point of view and have a predetermined destiny and faith. The reflection of Ferdowsi's determinism can be clearly observed in Rostam and Sohrab tragedy and also the story of Rostam and Esfandyar's battle. The belief in destiny in these sorts of stories is along with the unreliability of the world, the affectation and tricks of life and the power of death. Finally, I have insisted on the fact that Ferdowsi's pessimism about the world and its affairs does not prevent human beings from their struggles and does not make them unconcerned with life. It can only be possible through the determination and free will that the national epic poet of Iran could create the most valuable Shahnameh through thirty years days and nights.