The mystery of the Trinity is incomprehensible. The following anecdote is related of St. Augustine, the great theologian and Doctor of the Church.
For many nights and days he had been meditating on the mystery of the Holy Trinity; he was of the opinion that one must at length attain thorough knowledge and understanding of the doctrine. One day he was walking on the sea-shore, pondering on this subject, when he saw a little boy who was engaged in carrying some of the sea-water in a shell to a trench which he had dug. St. Augustine stopped and asked the child what he was doing.
He answered: “I want to empty all the water of the ocean into this pit.”
The saint shook his head, and said: “My child, that is impossible!”
The boy looked up and smiled. “It would be easier,” he replied, “to empty all the sea into this trench than to fathom the mystery of the Holy Trinity.”
Our finite intelligence can no more comprehend the nature of the infinite Deity than the waters of the ocean can be confined in a vessel of human manufacture.
Text from Francis Spirago, Anecdotes and Examples Illustrating the Catholic Catechism (New York: Benziger, 1904).