““Worldly success was a potent force in the growth of Islam, and in the shriveling of Christianity. That fact may be troubling to Christians, whose faith so often extols the triumph of the meek and humble while rejecting worldly success, and who are so familiar with the concept of defeat as the root of long-term victory. In practice, though, Christians often had used material successes as proofs of their faith. As we have seen, church writers pointed to miracles and healings to vouch for the power of Christ, and such events often explained important conversions. Though such claims continued to be made, they were increasingly outweighed by the obvious successes of Muslim states and armies. At several critical moments, Muslim victories proved enormously damaging to the Christian cause, from the early triumphs over the Byzantine Empire onward. As the early Islamic convert 'Ali Tabari explained, “[Muhammad’s] victory over the nations is also by necessity and by undeniable arguments a manifest sign of the prophetic office.”20 If God had not been on his side, how could Muhammad’s followers possibly have won such stunning victories over ancient empires?””