There are millions of hymn arrangements, for all sorts of ensembles. However, in my experience searching for intriguing, well-written, intermediate-advanced arrangements for viola and piano, I have discovered very little. So I have collaborated with six excellent composers to present a book of viola-piano hymn arrangements originally written for viola! Please note: these arrangements vary from Intermediate to very Advanced. 
 
Sample: https://www.youtube.com/watch?v=IFBcSUuGtms
 
Includes:
Jesus the Very Thought of Thee
Reverently and Meekly Now
All Things Bright and Beautiful
Be Thou My Vision (Take Time to be Holy)
Beautiful Savior
The King of Love My Shepherd Is
I Heard the Voice of Jesus Say (If You Could Hie to Kolob)