A list of sermons in date order is an archive nobody explores. Grouped into series, the same sermons become something a visitor browses, and finds the one they needed.
Start with Publish your first sermon if you have not posted one yet.
Making a series
On the Sermons page, open the Series tab and choose New Series. Give it a title, and optionally a description, cover artwork, and start and end dates. Then assign sermons to it as you publish them, using the Series field on the sermon form.
Artwork matters more than it should. A series grid with images looks like a library; the same grid without them looks like a spreadsheet, and people browse one and not the other. One image per series, reused across every sermon in it, is a small job with a large effect.
Current series
One series can be marked current. Open the series and press Set as Current. It is featured at the top of your public Messages page, and the member app uses it too. Setting a new series as current replaces the old one; there is no button to simply switch it off.
Set it when a new series starts. A church still featuring its Easter series in September is telling every visitor something it did not mean to.
Order
Sermons within a series have an order, so they read in the sequence they were preached rather than whatever order they were uploaded. Open the series and reorder them if you backfill an old series out of sequence.
Publishing
A series is a draft until published, like everything else. You can build one ahead of time (artwork, description, dates) and release it the week it starts.
An unpublished series has no page of its own and does not show in the series list. The sermons in it are not hidden by that: each sermon follows its own publish state. If a sermon has gone missing from your site, check the sermon's own state and date first.
Backfilling the archive
If you have years of sermons elsewhere, do not import them all before organising them. A hundred and forty sermons with no series is worse than nothing: it is a wall.
Better: pick the three or four series people actually ask for, build those properly with artwork and descriptions, and add the rest over time. A small well-organised archive is used; a large disorganised one is not.