/sermons

I have a website that uses SermonSpeaker. In the older version I got an url /page/speaker/2-a-speaker/sermons.

I made a new version of the old website and the new websites uses: /page/speaker/2-a-speaker#sermons

But /sermons in the end still works, but has a different design (different code I think?).

Well to make a long story short, I want to be able to send /page/speaker/2-a-speaker/sermons with a redirect (301) to /page/speaker/2-a-speaker or something like that.

How can I do that?

The old "/sermons" is the parameter for the layout. It was needed because the speaker view had separate layouts for the sermons and series lists.
With Joomla 3.x and Bootstrap I tried to do it within a single layout where you can toggle between the two lists. That's why it now uses an anchor to define the list shown.

A redirect should work without problems. You can do that within the .htaccess file with RewriteRules. Or you can use the redirect component within the Joomla backend to redirect from the old (expired) URL to the new one.