Gilbert was secretary of the American Unitarian Association (1908-1915). His works include:
- The Christian Doctrine of Non-Resistance, by Adin Ballou and Leo Tolstoi (editor)
- The Indestructible Faith, 1916
- Thanksgiving: A Sermon, 1918
Hymns
- O God, Our Dwelling Place
- O Troubled Sea of Galilee
Wanted
- Photo
- Date & place of birth & death
- Biography
- Burial place