The four large side stained glass windows of the church depict the symbols of the four evangelists: Matthew, Mark, Luke and John.
The head of a man - the symbol of Matthew, Apostle and Martyr. Matthew is called the divine man, since he teaches about the human nature of Christ and since his version of the Gospel begins with Jesus's paternal genealogy.
Mark, Martyr, is called the winged lion, since he informs us of the royal dignity of Christ and since his version of the Gospel begins: "The voice of one crying in the wilderness", (introducing the mission of St. John the Baptist) suggesting the roar of the lion. The lion, the dweller in the desert, is the emblematic of St. Mark.
An Ox depicts St. Luke, Martyr. Luke is called the winged ox, since he deals with the sacrificial aspects of Christ's life and since his version of the Gospel begins with the temple scene, the account of the priest Zachary. The sacrificial ox is the symbol of St. Luke.
An eagle depicts St. John, Apostle. John is called the rising eagle soaring far into the heavens, since his gaze pierces so far into the mysteries of heaven and since his version of the Gospel begins with a lofty prologue that is a poem of the Word become flesh. He carries us, in the opening words of his Gospel, to heaven itself: "In the beginning was the Word, and the Word was with God, and the Word was God".
Larger versions of these images can be found in the Photograph Gallery. Thanks to Tony Black for the information about these windows.