  Religiosity is a powerful force shaping human societies, affecting domains as
diverse as economic growth or the ability to cope with illness. As more
religious leaders and organizations as well as believers start using social
networking sites (e.g., Twitter, Facebook), online activities become important
extensions to traditional religious rituals and practices. However, there has
been lack of research on religiosity in online social networks. This paper
takes a step toward the understanding of several important aspects of
religiosity on Twitter, based on the analysis of more than 250k U.S. users who
self-declared their religions/belief, including Atheism, Buddhism,
Christianity, Hinduism, Islam, and Judaism. Specifically, (i) we examine the
correlation of geographic distribution of religious people between Twitter and
offline surveys. (ii) We analyze users' tweets and networks to identify
discriminative features of each religious group, and explore supervised methods
to identify believers of different religions. (iii) We study the linkage
preference of different religious groups, and observe a strong preference of
Twitter users connecting to others sharing the same religion.
