Crowley aimed big
Regardless of whether or not Thelema is a religion, that it has a church cannot be credibly disputed. And while one can quibble over precisely what it means to have a church, it's not negotiable that Crowley saw it as an essential vehicle for bringing the Law to the world. So much so that he tasked his most dedicated initiates with the duty of overseeing this church as its clergy. The scope of this church's laity encompasses the world as Thelema's most outwardly focused body.