There are many different ways in which religion has been defined. Different cultures have different religious traditions and associated doctrines, ceremonies and institutional organizations. Two of the main different approaches to religion are on the one hand the essentialist and on the other the functionalist approach. From the established tradition of studies on religion and the Internet, Heidi Campbell identified six thematic areas emerging, namely authority, authenticity, community, identity, ritual and religion. One obvious spiritual craving is the hope for immortality: in one way or another, most religions teach us that we may live forever, through a surviving soul or resurrection of the body itself. The chapter also presents an overview of the key concepts discussed in this book.