The theory of politology called Peripheralism, first formulated by Zhang Lei of the Chinese Taixue, states that the borderlands where two or more religions meet soon become the cradles of the greatest empires, as the tendency in such zones of conflict is for the institutions waging the conflicts to evolve in scale and strength at an accelerated pace relative to other regions. Though Dr. Lei initially devised his model solely to explain political trends in Xiyu (OOC: Eurasia west of China), other scholars have taken his work in unforeseen directions, with "interaction" (including conflict and more benign, even non-political forms of exchange) between alien traditions being credited with everything from the overshadowing of China's northern plains by its southern coast to the rise of the Mind-Awakening. Since it works so well in its broad strokes, let's apply it:
Without Gnosticism (let's say this takes place as a consequence of the Great Sophist Mani, who first dragged Gnosticism from the marshes of southern Mesopotamia and thrust it into the wider Asian consciousness, not doing such a thing) Christianity and Islam are the initial beneficiaries, but we cannot expect Central Asia to immediately become a theater of conflict between those faiths in the manner of the Eastern Mediterranean. Grecian Christianity had a hard enough time extending far beyond Grecia (OOC: the Byzantine realm, on the basis that its forerunners were "Hellenes" but became "Greek" after interaction with Rome) itself, and the great conversion of the Rusichans was yet to come. Meanwhile, the eastern frontier of Islam was but a loose coalition of Arabs and collaborationist native notables, many of whom could still remember the old faiths. Granted, Central Asia would always be relevant for the trade routes running through it, but the policing of trade routes can be easily entrusted to cooperative clients. Without the adoption of the distinctly uncooperative Gnosticism by the nascent Karluk confederation after the fall for the Gokturk Khaganate, the Umayyads may not have been as fervent about "consolidation" in the East-- and without the long-running conflict that decision engendered, the conflict which welded Sogdian business and administrative acumen with Turkic military strength, the world may have never seen the rise of the Johannid Ikhshidate, still referred to by Gnostics as the World-Empire.
Sure, the Johannids brought to West and East a brutal and uncompromising form of warfare. The leveling of Baghdad more or less permanently shifted Islam's center of gravity to Egypt, and the eastern armies of the Ikhshid ended the Zhao Dynasty in a single blow by burning their way to Taiyuan. But in establishing a realm encompassing all from northern China in the east to Barygaza in the south to the mouth of the Danube in the West, it may be said that the Gnostics turned the peoples of the world away from squabbling over the ruins of Rome (or of Late Antiquity in general) and toward... well, modernity may be anachronistic. But the ecumenic spirit of the modern world was indeed prefigured by the Johannids' continent-sized kingdom, and in a more practical sense it was the University of Yahia-Yohanna, established by the Khereid prince Chaghatay the Wanderer to consolidate the scattered caches of books gathered up by the fratricidal Johannid princes in the Last War of Succession, which was the birthplace of the Awakening.
And of course, this isn't even mentioning other events such as the Western Schism; some scholars believe it could have been avoided if the Papacy had not felt threatened enough by the Cathar heresies in his backyard to sign an anti-Johannid alliance of convenience with the Caliph in Egypt, but the dominant perspective is that the divides in medieval Europe would inevitably have produced some rival to Catholicism in the long run.
(OOC: I'm imagining the Johannids as uber-Seljuks that begin with campaigns into Persia in the late 900s but then extend their power into the Khazar lands, subjecting the Rus' princes; to keep the Chinese from threatening them in the Tarim Basin they attack the successors of the Tang with the aid of the Mongols. I'm imagining that they don't even keep China for that long, but their western domains (probably governed by a caste of administrators from all over, with a nucleus of Sogdians and Khorasanis from historically loyal Gnostic families) remain united and dangerous for longer than the Mongols or Seljuks did, maybe until the early 1300s.)
