Islam is currently the highest growing religion in many countries as well as the second highest religious minority in other nations. While Shintoism, Confucianism, Hinduism and Lamaism are also experiencing fantastic growth globally, it is largely due to high birth rates among existing adherents.
The exceptions are Catholicism (as opposed to Christianity), Buddhism and Paganism.
While Catholicism is expanding across the world, it is shrinking in Europe, the US, Canada, Australia, NZ and other western nations. It is further decreasing in Central and South America where Christian journals have been requesting international support for making Christianity more appealing for over a decade.
Buddhism has an attraction based on the concepts of 'meditation', 'inner peace' and 'solitude'. It experienced a 63% increase between 1934 to 1984 globally. While the religion allows adherents to isolate themselves from the world in general, it also espouses beliefs in the absence of a Creator, an afterlife, justice for the wrongs committed against people by those already in the grave/s and has no theocratic structure or system for governance.
Paganism on the other hand has seen a modest revival after a two thousand year silence. While there has been a proliferation of interest in 'paganism', its actual foundations are weak. There is no singular religion to speak of, ritual is not based on creed but on personal interest, there is little emphasis on rules/regulations and more on practice. There are no concepts of 'clergy', 'purpose of creation', 'congregational gatherings' and no 'scripture' to speak of. It is however to some degree involve the use of calling 'spirits' (Jinn) and the occult in rituals.