Facebook? Yes, Facebook. This 77-year-old great-grandfather has a page on Facebook. And he’s a preacher, besides. Facebook is no longer only for children and young people. One discovers that there are many useful ways to profit from this Web program. Pictures can be made available to any who wish to see them. One can post information of various sorts that all can read—and, if one wishes, the people who read, are able to post their answers or arguments. It is a tool of communication such as has...