I think one of the proofs of the Faith is that if the Gospels are fictitious, it is the most remarkable of fiction. Out of a rather brutal and coarse culture comes a story so sensitive, with such an insight into human nature, with so many allusions and interwoven symbols, with such drama and such lucid dialogue and surprising character development that there’s no explanation for it.
Even as fiction the Gospels are miraculous.
We don’t have fiction this complex and developed before the Gospels, and we don’t get anything close to them until Shakespeare, 1600 years later – and the atmosphere of his writing is directly inspired by these same Gospels. The Gospels make even the Old Testament look amateurish by comparison, as well as by comparison the modern “realistic” novels and problem plays seem hollow and fake.
So there is an argument for the truth of the Faith that is purely one of literary criticism, and it is a very strong argument.