The Church at this time is sometimes referred to as Catholic and sometimes as Roman Catholic. It was certainly both but not in the same sense that it would be after the Gregorian Reform in the 11th century. By that time the protests of someone like Claudius would most certainly have resulted in a death sentence.
He lived at a time when the Roman See did not wield universal political power. Voices of dissent and differentiation of practice could still flourish and though he was certainly criticized, he was in no physical danger. Because there wasn't an enforced uniformity Christians could still function within the larger Catholic community. But that time was rapidly coming to an end.
It would take the Lateran Councils, an empowered Pope and the Inquisition to bring about the monolithic and frankly totalitarian Roman Catholic Europe we know all too well. During that era the monarchs of Europe trembled at the fulminations and decrees which poured forth from the throne in Rome.
Claudius attacked many of the practices of his day which he viewed as little more than superstitions. The cross, a devotional symbol largely unknown to the early church had come into great prominence and he mocked its veneration and by way of satire suggested that people might venerate anything Jesus had contact with in the course of his life. We might as well venerate the womb of virgins, swaddling cloths, mangers, ships or donkeys. Certainly all of these things could point to aspects of Christ's person and work. Claudius is basically asking, what is the basis for determining what is proper? Is there a basis, or is it whatever suits our fancy? Can we invent symbols to incorporate into our worship?
Most historians seem to make a mockery of his argument and label him as puritanical, pedestrian and unoriginal, a fool who focused on silly minutiae as it were.
This only displays their ignorance as they have missed the heart of the argument. Claudius was also arguing against the veneration of images, the cult of saints, pilgrimages, the cross, and all such innovations rooted in a theology not built on Scripture. He also attacked the authority of the pope and implicitly the institution of the papacy. He was one of the last voices to appear 'above' the radar as it were and get away with it. Later such critics met terrible deaths and were persecuted by the Roman institution.
The cross is just a symbol but indeed symbolic of a shift in thinking or at least a theological implication that Claudius had evidently worked out.
The issue is that of authority. How do we determine the life and practice of the Church? Claudius speaks as one whose thinking is formed by Scripture. He understood that to innovate was to deny its authority. Using Scripture as a mere starting point for a larger philosophical system and tradition would ultimately bury the Scripture and obscure its authority. The institution of the Papacy was a perfect example of this. The Scholastic theology which soon followed the era of Claude would solidify Rome's authority as something that went beyond Scripture.
Is this really a big deal? Do we need to oppose crosses too? Is this a pressing issue? A Lutheran friend of mine cannot understand it, he wants to see the cross everywhere. He likes seeing them on the roadside etc... For him it's a kind of claim on the land and institutions. That sentiment is indicative of yet another problem.
I've never left a church over this issue but it's a crack, a fissure by which other errors enter. It's not at the heart of the gospel but there's a lesson, a necessary consideration. I would rather see the crosses removed because to me they represent a principle... a principle that says the symbols God has given are not enough. We have to come up with our own. It suggests we can supplement God's work and therefore the Scriptures are ultimately not sufficient.
Groups like the Lollards and some of the Reformers also grasped this and there's a long theological pedigree of cross-opposition. It has nothing to do with questioning the death and resurrection of Christ. The issue is authority and those who adhere strictly to Sola Scriptura would argue that if you want to symbolize Christ's death and resurrection the way to do so has already been ordained by God. The Lord's Supper shows his death till he come (1 Cor 11.26). Any innovative symbol which tries to portray this same truth can only detract from the full meaning and import of what God has already provided.
It is pleasing to note how you don't really see crosses in the catacombs. It wasn't a symbol utilized by the early church. You do see other symbols like the anchor mentioned in Hebrews 6, but you don't see them utilized in worship. What does that say that the cross was later adopted and utilized? What's the principle? How do we frame such questions? In light of what authority are they to be considered? That's the issue.
At the end of the day, the cross is nothing to get terribly upset about. It's not a point of orthodoxy but again there's a lesson an issue to be considered. Dismiss it at your own peril.
In their mockery of Claudius these historical commentators only demonstrate that they misunderstand the issue. The joke is on them.
In truth they don't want to follow through on the implications of Claudius' thought. It's unthinkable. It would mean the mainstream Church, the supposed glory of the Middle Ages was not a step in the progression of Western culture and civilization but a theological aberration and regression. The idea that the Church was an underground disenfranchised community is too upsetting to contemplate and destroys the narrative they wish to unfold.
He died sometime around 827 and was last known to have been at the Novalesa Abbey in the mountains west of Turin. He was a light in a period of great and growing darkness.