Navigate to your church home page and wait for the slide you want to edit to show up and click Edit Details button at top right of your slideshow. This will bring up the edit panel for that slide where you can edit its details.
Navigate down to the bottom of the panel. You will see these publish fields, as highlighted in the graphic below.
Once you are done setting these 2 fields in the graphic above as you wish, click Save (or Save & List) at the the top right of that panel.