system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What qualifies as a religion under the freedom of religion protection laws?

Recently I've been reading on reddit that it's not possible to do anything against scientology because of freedom of religion laws. I've also read the large number of cases of parents with unvaccinated children that can do that because of religious exemptions. 

But scientology is a corporation that was founded shortly ago and no religion had anything against vaccines since there were no vaccines when the sacred books were written!

So I was wondering.. Is there in the law something that specifies what qualifies as a religion and what doesn't? If it has to be old or what?
gpt
It has less to do with how old/established the religion itself is, but whether the religious practices infringe on someone else's rights. For instance, there have been a number of cases where parents opted to deny their children medical treatment and instead go for Christian faith healing, then were arrested for child abuse as a result.