City Church is a WordPress child theme for Builder, a premium WordPress theme created by iThemes. A child theme is simply a different design for an existing theme, and works with the original theme’s structure. That is helpful when you already have a great base (like Builder) and want to offer different designs within that.
The theme comes with staff and sermon post type features built in to help you display that content on your church site well. Like many of their themes, City Church use Gravity Forms and have specific styles for them. I like the variety of layouts you can choose from to determine how you want to display your content.