I just got through resetting my cookie. Why am I showing up as "guest?"

While I'm here again, WYSIWYG, I should second your mention of
Standin' In the Need of Prayer

Joshua Fit The Battle of Jericho,

Spirit of the Living God

Swing low, sweet chariot

Wings Of A Dove

Good Gospel Ship

Higher Ground
Whispering Hope

Other good ones are
Under His Wings
For The Beauty Of The Earth
Give Me Oil In My Lamp (especially the "Give me umption in my gumption, help me function" verse!)
I've Got The Joy, Joy, Joy, Joy, Down In My Heart
Down By The Riverside.

I also like "Little Moses"

BTW, when singing in groups that are of mixed religions, it is often (not always) possible to leave out some verses or modify the words toward a more ecumenical content.
(This will not work, of course, with "The Old Rugged Cross!" In fact, one of the silliest such attempts, I think, is in the current Unitarian Universalist Hymnal -- the song "O Little Town Of Bethlehem." The words have been changed from having the angels "proclaim the holy birth" to "proclaim the baby's birth"--which begs the question of why the angels are proclaiming the birth of a normal, non-holy baby!)