
The Epistle side windows represent four of the covenants God made with mankind. One with Adam, one with Noah, one with Abraham and one with Moses and the people Israel. "Covenant" is a Hebrew word meaning "binding pact" which God always adhered to and mankind never seemed to be able to.
This window presented the greatest challenge to the crafters. After all, it's only possible to get creation right once (and God already did that).
The clear bevel (symbolizing the pre-existence of the Trinity) is surrounded by black glass. This black glass signifies (Genesis 1:1-2), "the earth was without form and void".