Real historians will doubtless find plenty to quibble about with the broad sweep of the canvas that this video represents. And, to be sure, this ministry doesn't exactly have an objective approach to the history of Islam — in another post on its website, it looks forward to Syrian refugees being disabused of their "Muhammedan way of life."
The video begins with the Roman empire and shows Christianity sprouting up on its margins, then spreading elsewhere. Islam follows suit a bit later, moving rapidly through the crumbling Byzantine and Sassanian empires, through North Africa and into parts of Europe. They both inexorably expand thereafter.
Over the course of time, this green-white tableau gets interrupted by ruptures in the form of other hues — the purple rampages of the Mongols and the red splotch of Communism — but the video for the most part keeps it very simple.
The conflation of political boundaries and cultural spheres can be confusing throughout: In some instances, the reach of a religion is certainly political, such as Rome's acceptance of Christianity in the 4th century or the spread of the Caliphate in the first few centuries after the advent of Islam.
But elsewhere, particularly when gazing at centuries of supposed Christian expansion in Asia, it seems a gross exaggeration. Christianity was never the major religion farther east, but rather present through small communities of traders and missionaries. The same is also somewhat true for Islam's role across vast swaths of Africa and Southeast Asia in the centuries after its birth.
India, which represents almost a sixth of humanity, is hardly a Christian nation (as it appears in the last frame of the map). Rather it is majority-Hindu and has a far greater number of Muslims than Christians within its borders.