The fact remains, that the overwhelming majority of the subject population, descendants of the Hispaniae of Roman times, where Catholics ; even though their influence was limited in the Visigothic Arian court (in fact the Suevi, the other Germanic tribe to settle in Spain, had already been converted to Catholicism even before the Goths).
In the late 6th century Visigothic Spain was brought into the Catholic fold, like most of the barbarian kingdoms, by a Catholic princess. Ingunthis, of the Merovingian court, was married to Hermengild, son of Leovigild king of the Goths. It would seem that, as did Clovis over Clotilda, Hermengild fell in love with Ingunthis. His Catholic wife, with the help of St. Leander Bishop of Seville, brought him to the true Church of God. This lead to a quasi civil war between son and father, the latter who wanted Hermengild to recant and come back to Arianism. The Catholic peasants of course favored Hermengild and proclaimed him king though neither he nor his father were willing to move directly against the other at first. Eventually though war did breakout and Hermengild was captured, offered the chance to apostatize, he refused and was martyred in 585 ad. Nevertheless his brother Reccared, who inherited the throne on the death of Leovigild the next year, was also sympathetic to his brothers faith. He had his brother's murderers executed and in 587 convened a synod of both Arian and Catholic Bishops in which he announced his own conversion (he had also been instructed in the faith by St. Leander).
The Council of Toledo in 589 spells it out clearly We confess, then, that we are converted to the catholic Church from the Arian heresy, with all our hearts, with all our soul and with all our mind. (García Villada, Historia eclesiástica de Españ, II, p 71.).
So, Spain is Catholic, however you want to cut it, BFORE the Muslims bloody invasion in the 8th century. period. Go find some other thread to post your Muslim lies on.
Not all historians buy into this business of a period of time devoid of substantial manuscripts as being anything other than a "dark age".
As far as Spain being fully Roman Catholic BEFORE the Moslem Invasion, we really don't know very much at all about Spain from roughly 541 to 711, a vast environmental or climate disaster having occured earlier wiping out civilization in most of Northern and Western Europe.
The remaining documents not burned in the hearth to keep warm are not a fair or representative sample of either the news or the level of civilization in the region.
It really isn't surprising to find a document found elsewhere attesting to something that may, in fact, not have happened ~ to wit, the total conversion of the Arian Christians to Rome ~
This period of time is more appropriately handled by archaeology than history anyway.
BTW, one of the things we don't know about the Iberian peninsula is if the Celts who dominated the North followed Roman, Orthodox or "Irish" liturgical traditions. On the other hand, the Cronish who came later did (not that they were really opposed to Rome, but who could check up on them without wading through a Moslem Sea.).