In the catholic tradition there's a view on jesus's sacrificial role that interprets it as the last human ritual sacrifice. For long the religions of the region had transitioned from human to animal sacrifice. Greeks, Romans, Judaism and, later, Islam all used animal sacrifice as offerings to god. Jesus's death was the human sacrifice to end all ritual sacrifices and replace them with symbolic offerings, like wax candles, flowers and behavioral sacrifices in the form of penance and prayer. Or the consumption of wine and wafers (body and blood of Christ) instead of ritual consumption of blood, meat and fats of sacrificed animals.

It's a shitty explanation that comes from anthropological analysis, but it is an explanation alright.