Is there any difference between selected private ads, secret society and religion? It's quite similar. Subgroup of crowd, believing something may not be scienti

Is there any difference between selected private ads, secret society and religion? It's quite similar. Subgroup of crowd, believing something may not be scientific, xenophobia, delivering some "special idea" to their members, etc. If there is no illegal stuff, why should we criticize on this? Just because they are not mature or long enough as religion?