The St. John Window
St. John is represented by the eagle as his Gospel is said to soar on eagles' wings to the very throne of heaven. The small serpent below is a referrence to the legend of an attempt to murder St.John by poisoning the wine in the communion chalice. The poison took the form of a serpent and crawled away.
Information on the stained glass windows comes from the book "The Windows and Symbolism of First Methodist Church, Birmingham, Michigan", edited by Dr. Arnold F. Runkel and privately published by the church for its members in 1966.