Indeed, so far from the development of the Christian Church being hampered by the establishment of Muhammadan rule, the history of the Nestorians exhibits a remarkable outburst of religious life and energy from the time of their becoming subject to the Muslims.[100] Alternately petted and persecuted by the Persian kings, in whose dominions by far the majority of the members of this sect were found, it had passed a rather precarious existence and had been subjected to harsh treatment, when war between Persia and Byzantium exposed it to the suspicion of sympathising with the Christian enemy. But, under the rule of the caliphs, the security they enjoyed at home enabled them to vigorously push forward their missionary enterprises abroad. Missionaries were sent into China and India, both of which were raised to the dignity of metropolitan sees in the eighth century; about the same period they gained a footing in Egypt, and later spread the Christian faith right across Asia, and by the eleventh century had gained many converts from among the Tatars.[101]
If the other Christian sects failed to exhibit the same vigorous life, it was not the fault of the Muhammadans. All were tolerated alike by the supreme government, and furthermore were prevented from persecuting one another.[102] In the fifth century, Barsauma, a Nestorian bishop, had persuaded the Persian king to set on foot a fierce persecution [[69]]of the Orthodox Church, by representing Nestorius as a friend of the Persians and his doctrines as approximating to their own; as many as 7800 of the Orthodox clergy, with an enormous number of laymen, are said to have been butchered during this persecution.[103] Another persecution was instituted against the Orthodox by K͟husrau II, after the invasion of Persia by Heraclius, at the instigation of a Jacobite, who persuaded the King that the Orthodox would always be favourably inclined towards the Byzantines.[104] But the principles of Muslim toleration forbade such acts of injustice as these: on the contrary, it seems to have been their endeavour to deal fairly by all their Christian subjects: e.g. after the conquest of Egypt, the Jacobites took advantage of the expulsion of the Byzantine authorities to rob the Orthodox of their churches, but later they were restored by the Muhammadans to their rightful owners when these had made good their claim to possess them.[105]
In view of the toleration thus extended to their Christian subjects in the early period of the Muslim rule, the common hypothesis of the sword as the factor of conversion seems hardly satisfactory, and we are compelled to seek for other motives than that of persecution. But unfortunately very few details are forthcoming and we are obliged to have recourse to conjecture.[106] In an age so prolific of theological speculation, there may well have been some thinkers whose trend of thought had prepared them for the acceptance of the Muhammadan position. Such were those Shahrīghān or landed proprietors in Persia in the eighth century, who were nominally Christians, but maintained that Christ was an ordinary man and that he was as one of the Prophets.[107] They appear at times to have given a good deal of trouble [[70]]to the Nestorian clergy, who were at great pains to draw them into the paths of orthodoxy;[108] but their theological position was more closely akin to Islam than to Christian doctrine, and they probably went to swell the ranks of the converts after the Arab conquest of the Persian empire.
Many Christian theologians[109] have supposed that the debased condition—moral and spiritual—of the Eastern Church of that period must have alienated the hearts of many and driven them to seek a healthier spiritual atmosphere in the faith of Islam which had come to them in all the vigour of new-born zeal.[110] For example, Dean Milman[111] asks, “What was the state of the Christian world in the provinces exposed to the first invasion of Mohammedanism? Sect opposed to sect, clergy wrangling with clergy upon the most abstruse and metaphysical points of doctrine. The orthodox, the Nestorians, the Eutychians, the Jacobites were persecuting each other with unexhausted animosity; and it is not judging too severely the evils of religious controversy to suppose that many would rejoice in the degradation of their adversaries under the yoke of the unbeliever, rather than make common cause with them in defence of the common Christianity. In how many must this incessant disputation have shaken the foundations of their faith! It had been wonderful if thousands had not, in their weariness and perplexity, sought refuge from these interminable and implacable controversies in the simple, intelligible truth of the Divine Unity, though purchased by the acknowledgment of the prophetic mission of Mohammed.” Similarly, Caetani sees in the spread of Islam, among the Christians of the Eastern Churches, a revulsion of feeling from the dogmatic subtleties introduced into Christian theology by the Hellenistic spirit. “For the East, with its love of clear and simple concepts, Hellenic culture was, from the religious point of view, a misfortune, because [[71]]it changed the sublime and simple teachings of Christ into a creed bristling with incomprehensible dogmas, full of doubts and uncertainties; these ended with producing a feeling of deep dismay and shook the very foundations of religious belief; so that when at last there appeared, coming out suddenly from the desert, the news of the new revelation, this bastard oriental Christianity, torn asunder by internal discords, wavering in its fundamental dogmas, dismayed by such incertitudes, could no longer resist the temptations of a new faith, which swept away at one single stroke all miserable doubts, and offered, along with simple, clear and undisputed doctrines, great material advantages also. The East then abandoned Christ and threw itself into the arms of the Prophet of Arabia.”[112]
Again, Canon Taylor[113] says: “It is easy to understand why this reformed Judaism spread so swiftly over Africa and Asia. The African and Syrian doctors had substituted abstruse metaphysical dogmas for the religion of Christ: they tried to combat the licentiousness of the age by setting forth the celestial merit of celibacy and the angelic excellence of virginity—seclusion from the world was the road of holiness, dirt was the characteristic of monkish sanctity—the people were practically polytheists, worshipping a crowd of martyrs, saints and angels; the upper classes were effeminate and corrupt, the middle classes oppressed by taxation,[114] the slaves without hope for the present or the future. As with the besom of God, Islam swept away this mass of corruption and superstition. It was a revolt against empty theological polemics; it was a masculine protest against the exaltation of celibacy as a crown of piety. It brought out the fundamental dogmas of religion—the unity and greatness of God, that He is merciful and righteous, that He claims obedience to His will, resignation and faith. It proclaimed the responsibility of man, a future life, a day of judgment, and stern retribution to fall upon the wicked; and enforced the duties of prayer, almsgiving, fasting and [[72]]benevolence. It thrust aside the artificial virtues, the religious frauds and follies, the perverted moral sentiments, and the verbal subtleties of theological disputants. It replaced monkishness by manliness. It gave hope to the slave, brotherhood to mankind, and recognition to the fundamental facts of human nature.”
Islam has, moreover, been represented as a reaction against that Byzantine ecclesiasticism,[115] which looked upon the emperor and his court as a copy of the Divine Majesty on high, and the emperor himself as not only the supreme earthly ruler of Christendom, but as High-priest also.[116] Under Justinian this system had been hardened into a despotism that pressed like an iron weight upon clergy and laity alike. In 532 the widespread dissatisfaction in Constantinople with both church and state, burst out into a revolt against the government of Justinian, which was only suppressed after a massacre of 35,000 persons. The Greens, as the party of the malcontents was termed, had made open and violent protest in the circus against the oppression of the emperor, crying out, “Justice has vanished from the world and is no more to be found. But we will become Jews, or rather we will return again to Grecian paganism.”[117] The lapse of a century had removed none of the grounds for the dissatisfaction that here found such violent expression, but the heavy hand of the Byzantine government prevented the renewal of such an outbreak as that of 532 and compelled the malcontents to dissemble, though in 560 some secret heathens were detected in Constantinople and punished.[118] On the borders of the empire, however, at a distance from the capital, such malcontents were safer, and the persecuted heretics, and others dissatisfied with the [[73]]Byzantine state-church, took refuge in the East, and here the Muslim armies would be welcomed by the spiritual children of those who a hundred years before had desired to exchange the Christian religion for another faith.
Further, the general adoption of the Arabic language throughout the empire of the caliphate, especially in the towns and the great centres of population, and the gradual assimilation in manners and customs that in the course of about two centuries caused the numerous conquered races to be largely merged in the national life of the ruling race, had no doubt a counterpart in the religious and intellectual life of many members of the protected religions. The rationalistic movement that so powerfully influenced Muslim theology from the second to the fifth century of the Hijrah may very possibly have influenced Christian thinkers, and turned them from a religion, the prevailing tone of whose theology seems at this time to have been Credo quia impossibile. A Muhammadan writer of the fourth century of the Hijrah has preserved for us a conversation with a Coptic Christian which may safely be taken as characteristic of the general mental attitude of the rest of the Eastern Churches at this period:—
“My proof for the truth of Christianity is, that I find its teachings contradictory and mutually destructive, for they are repugnant to reason and revolting to the intellect, on account of their inconsistency and mutual contrariety. No reflection can strengthen them, no discussion can prove them; and however thoughtfully we may investigate them, neither the intellect nor the senses can provide us with any argument in support of them. Notwithstanding this, I have seen that many nations and mighty kings of learning and sound judgment, have given in their allegiance to the Christian faith; so I conclude that if these have accepted it in spite of all the contradictions referred to, it is because the proofs they have received, in the form of signs and miracles, have compelled them to submit to it.”[119]
On the other hand, it should be remembered that those who passed over from Christianity to Islam, under the influence of the rationalistic tendencies of the age, would [[74]]find in the Muʻtazilite presentment of Muslim theology, very much that was common to the two faiths, so that as far as the articles of belief and the intellectual attitude towards many theological questions were concerned, the transition was not so violent as might be supposed. To say nothing of the numerous fundamental doctrines, that will at once suggest themselves to those even who have only a slight knowledge of the teachings of the Prophet, there were many other common points of view, that were the direct consequences of the close relationships between the Christian and Muhammadan theologians in Damascus under the Umayyad caliphs as also in later times; for it has been maintained that there is clear evidence of the influence of the Byzantine theologians on the development of the systematic treatment of Muhammadan dogmatics. The very form and arrangement of the oldest rule of faith in the Arabic language suggest a comparison with similar treatises of St. John of Damascus and other Christian fathers.[120] The oldest Arab Ṣūfīism, the trend of which was purely towards the ascetic life (as distinguished from the later pantheistic Ṣūfīism) originated largely under the influence of Christian thought.[121] Such influence is especially traceable in the doctrines of some of the Muʻtazilite sects,[122] who busied themselves with speculations on the attributes of the divine nature quite in the manner of the Byzantine theologians: the Qadariyyah or libertarians of Islam probably borrowed their doctrine of the freedom of the will directly from Christianity, while the Murjiʼah in their denial of the doctrine of eternal punishment were in thorough agreement with the teaching of the Eastern Church on this subject as against the generally received opinion of orthodox Muslims.[123] On the other hand, the influence of the more orthodox doctors of Islam in the conversion of unbelievers is attested by the tradition that twenty thousand Christians, Jews and Magians became Muslims when the great Imām Ibn Ḥanbal died.[124] A celebrated [[75]]doctor of the same sect, Abu’l-Faraj b. al-Jawzī (A.D. 1115–1201), the most learned man of his time, a popular preacher and most prolific writer, is said to have boasted that just the same number of persons accepted the faith of Islam at his hands.[125]
Further, the vast and unparalleled success of the Muslim arms shook the faith of the Christian peoples that came under their rule and saw in these conquests the hand of God.[126] Worldly prosperity they associated with the divine favour and the God of battle (they thought) would surely give the victory only into the hands of his favoured servants. Thus the very success of the Muhammadans seemed to argue the truth of their religion.