My Church Events calendar services are fine if you can maintain them. Another option I suggest is to use using Google Calendar with separate calendars for various events if you want to be able to filter out some of the extraneous events that some members find important to post. They could post their calendars on their pages and the overall calendar could focus on the particular events you want visible to the public. If you use Google Calendar, you can control what goes on your site and allow specific people access to specific calendars PLUS remove those people when they move on.