The old waiter’s interpretation of the prayer shows his depression and loss of faith. At a deeper level, it is a manifest of “nothingness” that waits for us at every corner. The protagonist realizes that religion offers little help in his fight with depression, but he does not know what else he could do.
In the short story, Hemingway shows that for many people, life has no meaning. The waiter and visitor hide from their inner emptiness in the well-lit café. For the first, it is his job, and for the second, it is a place to get drunk. The waiter and the visitor represent different stages of the same type of depression. It is likely that in some ten to fifteen years, the waiter would drink in a café till he is drunk. But now, he can still analyze his condition.
The Lord’s Prayer is his self-analysis and introspection. He recites the most famous prayer, substituting every other word with nada (nothing in Spanish). In such a way, he says that religion means nothing, despite that millions of people find their purpose in life in faith. Instead of “Our Father who art in heaven,” the waiter says, “Our nada who art in nada.” In a single sentence, he ruins the idea of God and heaven.
Then the older waiter summarizes the prayer in the following words: “It was all a nothing and man was a nothing too.” Religion is an ineffective treatment from despair, but humanity has not invented anything better so far.