If you looked at our stained glass windows could you tell what they are about? The window over the altar has a chalice and host and so it reminds us of Jesus' Body and Blood. The window also has a bible that reminds us of the Word of God. Put them together and we have the Mass. Can you also see the cross? This reminds us of Jesus’ death and resurrection.
Take a look at the window on the east side. What do you see? A dove reminds us of the Holy Spirit. Tongues of fire also remind us of the Holy Spirit. The rays show us the Spirit coming down on the Apostles and on us in Confirmation.
Take a look at the window on the west side. What do you see? The Alpha (the first letter of the Greek alphabet), and the Omega (the last letter of the Greek alphabet). God is first and God is last. He never started and He will never end. The rays remind us that God creates us and pours himself into us.
Put all the windows together and what do you get? God the Father, God the Son, and God the Holy Spirit.