It is a religion. Note that Orthodoxy, like other branches of Judaism, is not homogeneous. Broadly speaking, Orthodox Judaism is divided into the Modern Orthodox, Jews who observe Jewish law but do not separate themselves from the secular world or modernity, and the Hassidic community. There are many different Hassidic groups, all the product of a pietist movement that was born in the 18th century in Ukrane. Hassidism has strong connections to Kabbala, and Hassidic Jews reject many aspects of modernity. Some Hassidic groups do have strong cult-like aspects, including focus on a single charismatic leader.