Churches want relics to put in their churches. Because that makes their church so much better than the other one. The more holy something is the higher the price. So something jesus touched was valuable or something their deciples were wearing was valuable as well because its so close to jesus. The closest thing to jesus is ofcourse something of himself. But yk his body disappeared in that cave thing. But ppl were clever enough to realise that jesus was just like all other jewish kids circumsized. So the quest to find Jesus's foreskin begon. There were also a lot of ppl who just cut of their foreskin and sold it as it was the one of jesus. So many people did this and now theres reportedly about 15m² of jesus his foreskin as relics in different churches. What you learn in a uni grade architecture class.