Over the central doors in the nave are three stone panels.

In the center panel, there are four symbols relating to the four marks of the Catholic Church. These marks, or attributes, can be found in the Nicene Creed professed at Mass every Sunday: "We believe in one, holy, catholic, and apostolic Church."

(1) The papal tiara in the upper left, representing the pope, under whom all the Church is united, symbolizes unity (one).

(2) The dove in the upper right, representing the Holy Spirit, who is the divine soul of the Church, symbolizes the holiness of the Church.

(3) The miter and crozier in the lower left, indicating the office of all bishops, who represent the successors to the Apostles, symbolizes the apostolic mark of the Church. 

(4) The planet earth in the lower right, symbolizes "catholic", i.e., the small 'c' means that the Church is universal and is called to save all people.

	To the right is a depiction of the Old Testament Tree of Life, with the hand of God giving the Law (symbolized by the Ten Commandments) and the prophets (symbolized by the scroll) along with other Old Testament motifs, such as the serpent and the psalmist's harp.
	To the left is the New Testament Tree of Life, which shows a symbol of the Trinity over the tree, a Gospel book containing the emblems of the four evangelists (Matthew as a man; Mark as a lion; John as an eagle and Luke as a bull). Beneath the book, Jesus is symbolized as the Lamb of Sacrifice, while the bread and fish are symbolic of the sacrifice at Calvary -- the Eucharist -- by which we are nourished.

There are two more panels to see here.