But the Muslim creed was most eagerly welcomed by the townsfolk, the industrial classes and the artisans, whose occupations made them impure according to the Zoroastrian creed, because in the pursuance of their trade or occupations they defiled fire, earth or water, and who thus, outcasts in the eyes of the law and treated with scant consideration in consequence, embraced with eagerness a creed that made them at once free men, and equal in a brotherhood of faith. [693] Nor were the conversions from Zoroastrianism itself less striking: the fabric of the National Church had fallen with a crash in the general ruin of the dynasty that had before upheld it; having no other centre round which to rally, the followers of this creed would find the transition to Islam a simple and easy one, owing to the numerous points of similarity in the old creed and the new. For the Persian could find in the Qurʼān many of the fundamental doctrines of his old faith, though in a rather different form: he would meet again Ahuramazda and Ahriman under the names of Allāh and Iblīs; the creation of the world in six periods; the angels and the demons; the story of the primitive innocence of man; the resurrection of the body and the doctrine of heaven and hell. [694] Even in the details of daily worship there were similarities to be found and the followers of Zoroaster when they adopted Islam were enjoined by their new faith to pray five times a day just as they had been by the Avesta. [695] Those tribes in the north of Persia that had stubbornly resisted the ecclesiastical organisation of the state religion, on the ground that each man was a priest in his own household and had no need of any other, and believing in a supreme being and the immortality of the soul, taught that a man should love his neighbour, conquer his passions, and strive patiently after a better life—such men could have needed very little persuasion to induce them to accept the faith of the Prophet. [696] Islam had still more points of contact with some of the heretical sects of Persia, that had come under the influence of Christianity. In addition to the causes above enumerated of the rapid spread of Islam in Persia, it should be remembered that the political and national sympathies of the conquered race were also enlisted on behalf of the new religion through the marriage of Ḥusayn, the son of ʻAlī with Shāhbānū, one of the daughters of Yazdagird, the last monarch of the Sāsānid dynasty. In the descendants of Shāhbānū and Ḥusayn the Persians saw the heirs of their ancient kings and the inheritors of their national traditions, and in this patriotic feeling may be found the explanation of the intense devotion of the Persians to the ʻAlid faction and the first beginnings of Shīʻism as a separate sect. [697]