The Cathedral's hand-blown glass windows were designed and made at a studio and furnace established in Bryn Athyn. The lost art of making pot metal glass was revived in order to duplicate the vibrant colors and textures of medieval stained glass.
As early as 1914, Raymond Pitcairn had begun thinking about the stained glass windows for the Cathedral. Determined to reproduce the textures and pure colors of the early Gothic French windows he admired during his trips to Europe researching construction, he arranged for the translation of a twelfth-century manuscript on the subject to revive the medieval art of making pot metal glass.
His artists were sent to England and France to photograph and draw windows in specified churches. He also sent them to see a stained glass collection of a friend, in order to provide them with a hands-on view of medieval panels.
Stained glass craftsmen were sought and set to work experimenting with colors recipes before they moved on to create the hand-blown windows seen in the Cathedral today.
The windows, while medieval by design, depict distinctive New Church doctrines.
- Old Testament windows in the nave clerestory include figures of Adam and Eve, Noah, Abraham, David and others not merely as illustrations of Bible stories, but also for what they represent. Paired with an angel messenger, they represent the manner in which the Lord speaks to us today in Old Testament sphere.
- New Testament windows in the chancel clerestory show a changing relationship between human beings and the Divine, as the Lord lives within us and teaches directly about Himself.
- The east window in the inner sanctuary, showing the Lord Jesus Christ and the twelve apostles, is derived from the visions of John as written in the book of Revelation. This represents a fuller understanding of Christianity and fuller relationship between God and Humans.