system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are old "religions"(norse, pagan etc.) are not considered religions today, when Christianity, Islam etc. is and they have pretty much the same proofs for their beliefs?
gpt
A religion isn't just the things people believe, it's the institution to act in accordance with that belief. That is, Christianity isn't *just* the belief that Jesus lived and taught in Galilee, was crucified by the Romans, and was resurrected, liberating some or all people from some or all of the consequences of sin. It's the whole apparatus of believers and churches and Mass and revival meetings and Bible study groups.

Norse or Greco-Roman paganism doesn't have that in the modern world (except for a few revivalist movements, which most people would agree are religions, even if they think they're silly). The Elusinian Mysteries aren't performed. No one goes to Delphi or Cumae or Dodona to consult with an oracle. There are no Vestal Virgins. The last vestiges of the actual practice of Roman paganism died off in the five or six hundreds.