Saint Jerome in his sermon on Psalm 41 gave an immortal reflection on the Trinity:
Like a deer that longs for springs of water, so my soul longs for you, O God. Now just as those deer long for springs of water, so do our deer. Fleeing Egypt – that is, fleeing worldly things – they have killed Pharaoh and drowned all his army in the waters of baptism.
Now, after the devil has been killed, they long for the springs of the Church: the Father, the Son, and the Holy Spirit.
We can find the Father described as a spring in Jeremiah: They have abandoned me, the fountain of living water, to dig themselves leaky cisterns that cannot hold water.
About the Son we read somewhere: They have forsaken the fountain of wisdom.
Finally, of the Holly Spirit: Anyone who drinks the water that I shall give will have a spring inside him, welling up to eternal life. Here the evangelist is saying that the words of the Saviour come from the Holy Spirit. So you see it very clearly confirmed that the springs that water the Church are the mystery of the Trinity.
These are the springs that believers long for. These are the springs that the souls of the baptized seek, saying My soul thirsts for God, the living God. The soul does not just feel like seeing God, it longs for him fervently, it is on fire with thirst for him. Before they received baptism, the catechumens spoke to each other and said, When shall I come and stand before the face of God? What they asked for has now been given them: they have come and stood before the face of God.
They have come before the altar and been confronted by the mystery of the Savior.
Welcomed into the body of Christ and reborn in the springs of life, they confidently say: I will go up to your glorious dwelling-place and into the house of God. The house of God is the Church, the ‘dwelling-place’ where dwells the sound of joy and thanksgiving, the crowds at the festival.
So then, you who have followed our lead and robed yourselves in Christ, let the words of God lift you out of this turbulent age as a net lifts the little fishes out of the water. In us the laws of nature are turned upside down – for fish, taken out of the water, die; but the Apostles have fished us out of the sea that is this world not to kill us but to bring us from death to life. As long as we were in the world, our eyes were peering into the depths and we led our lives in the mud. Now we have been torn from the waves, we begin to see the true light. Moved by overwhelming joy, we say to our souls: Put your hope in the Lord, I will praise him still, my savior and my God.