The answer is; Wind
They drive atmospheric circulation. The sun does not heat the earth evenly. The parts that are heated up more form the low-pressure systems where air masses move in from high-pressure systems to form winds. These air masses are also deflected by Coriolis effect caused by earth’s rotation.
A universalizing religion attempts to be global, to appeal to all people, wherever they may live in the world, not just to those of one culture or location and an ethnic religion appeals primarily to one group of people.
One way would be to limit who can receive a passport or visa to travel to another country and another would be at the entrance to the country they may not be admitted for example due to inadequate funds to live. In my case, when I travelled by bus from Costa Rica to Panama, the Panamanian authorities required that I either have a ticket out of the country or a return ticket back to San Jose, Costa Rica.
C The coast with lake victoria.