There was a comment earlier that got deleted, but I was already writing a reply. Hopefully this draft is helpful.

The history of relics is quite interesting, believe it or not, and not just because they speak to the universal human appreciation for closeness to greatness. Think of the cult of celebrity today as a contemporary example, of which autograph collections are the most benign extreme.

Relics arise from the cult of the martyrs and seem to precede the use of almost every Christian symbol---by which I mean religious art and iconography. The earliest document written by a Christian woman is the Passion of Perpetua, an account of her visions while awaiting martyrdom. All but one of the Twelve Apostles was martyred, and the remaining Apostle died in exile.

Notably, martyrs after all were not always killed immediately, if that ever happened. Generally, you could visit them in prison. Other Christians would, often to gain advice or guidance or intercession in disputes with other Christians, sometimes to obtain forgiveness. Forgiveness for what? Well, martyrs were in jail for staying true to Christ---ever wonder what happened to those who gave in under pressure? Well, at least some of them went to the martyrs in prison. Depending on which historian you listen to, this was an end-run around the extreme penances of Early Christianity, and bishops were uneasy or at least challenged by this process. Nobody could deny the logic of revering a martyr!

For a religion believing in the death of God and then the resurrection of his fleshly body in anticipation of the general resurrection, the remaining body of the holy one (from Latin, we say saint) after martyrdom was is not just part of that saint but also the very act which gave them sanctity. This death was a gift from God which they gratefully received. As Christ was killed, so were they killed, and by dying for Christ they were guaranteed salvation. This was a big deal when it seems that early Christians thought salvation very rare, very unsure---Ignatius seems to beg people not to release him, as if his coming martyrdom is his only shot for salvation.

Conjecture: Evidence for the idea of a continued presence/significance within the relic is probably around somewhere, considering that this cult of martyrs eventually evolved into the Eastern Orthodox theory of iconography. In later iconography, icons are not religious art but a true presence of what it depicts. (However, that might develop instead from a robust early Christian view of the Real Presence in the Eucharist. Whenever texts are limited, there is always a ton of conjecture, and this conjecture is very often based off of some limb of some branch of some consensus built on some set of assumptions cobbled together and easy to take for granted.)

TLDR: Religious art comes from the cult of the martyrs, which comes from relics, which comes from imprisoned martyrs-to-be.

When early Christians stopped following Jewish dietary law, do we have any records of how the introduction of pork and other “unclean” foods effected their cuisine? Was it a big selling point that this Jesus fellow says you can have bacon, or was abandoning the kosher diet a minor issue?

So I have been reading about Cassiodorus the other day, and stumbled upon these sentences in his Wikipedia article (which is great btw. if the author reads this):

This inspired him to adjust his educational program to support the aesthetic enhancement of manuscripts within the monastery, something which had been practiced before, but not in the universality that he suggests.

[...]

Cassiodorus' legacy is quietly profound. Before the founding of Vivarium, the copying of manuscripts had been a task reserved for either inexperienced or physically infirm devotees, and was performed at the whim of literate monks. Through the influence of Cassiodorus, the monastic system adopted a more vigorous, widespread, and regular approach to reproducing documents within the monastery.[24] This approach to the development of the monastic lifestyle was perpetuated especially through German religious institutions.

So does this mean this Cassiodorus is one of the people that founded or popularized the tradition of richly decorated bibles and holy manuscripts?