I recently came across the website, Koerts Music which has some really wonderful free arrangements of hymns and even an arrangement of "Joy to the World". I printed a couple of them, sat down at the piano to play through them and then went back and printed them all!
Each arrangement is really enjoyable to play and I can think of several ways to use them in Sunday morning services both for my students and for myself. I would say they fall under, "Late Intermediate or Early Advanced". I encourage you to take a look and try them for yourself!
Have a wonderful weekend!