return sort fields instead of echo

[Jack Lamb]

to fix display of shortcode

[Tim Hyde]

This isn't a "sort". It is a "filter".

also is there a way to add the filter to the sermons archive when not using the views?

[Jack Lamb]

Just call this in your theme files

wpfc_sermons_sorting_shortcode();

you're right about the terminology :)

[Jack Lamb]

fixed in 1.8