"The history of Christianity in Spain may have to be rewritten", according to the Gurniad, after the discovery of a paten which predates the arrival of the "Christianised" Visigoths in the 5th Century. To be fair, the Guarniad does resist the urge to say the history has been "turned upside down". But I bet it was a close-run thing.
Well, a few things to consider. The Visigoths were Arians, not orthodox Christians. When they arrived in Spain, the Catholics were already there. Spain, being a part of the Roman Empire, had had Christianity as its official religion from the 4th Century. In fact, Christianity was in the province of Hispanica long before that, even - apart from the legends about St James, we have other references to Spanish Christian communities, from Irenaeus of Lyons and Cyprian.
So finding evidence of Christianity in Spain from before the Visigoths adds precisely nothing to our knowledge.
When it comes to religion, with the honorable exception of Andrew Brown, the Guardian doesn't know its apse from its ambo.