One of the advantages of wordpress (and other blogging tools) is that an RSS feed is automatically created when news or other items are posted and this new info is then pinged to various sites that record updated websites.
By using wordpress this process is automated, and there is no longer a need to wait for visitors to stumble across the updates or to wait for the googlebot to visit, because they can subscribe to the feed and receive notifications.
However, search engines do not appear to use updated feeds to determine when they crawl a site, but have there own methods. Google has recently introduced a sitemap feature so that webmasters can provide information to the googlebot for more complete searches.
And A9 has done something similar for users of the A9 toolbar. Having an A9 siteinfo file allows users of the toolbar to see an archive of all the pages available.
It remains to be seen whether either of these features will take off in a big way, but there are two plugins from Arne Brachhold that incorporate these features (and pings google) without webmaster input. I.e. exactly the same way the RSS feed is created in wordpress.
Although incorporating these features may not have an immediate inpact on a church site, anything that helps google index the site or improve a user’s experience should be welcomed.