Religions emerge from the persistence of our separation from equanimity; this emergence is typically triggered by a sub-cultural crisis. Religions persist for as long as their adherents believe that theirs is capable of closing this separation. Religions evolve with the cultures in which they emerge, or into which are transplanted; they cannot drive this evolution while they assert that their doctrines are timeless. Religions decline and fail because of a widening gap between their doctrines and those of their encompassing cultures.

The power and persistence of any religion is based on its inspiring power.

Jews have the tradition of constantly transmitting their beliefs. These pass from generation to generation. Christianity is born within the Jewish people and adopts this tradition. The organizational scheme of the Catholic Church is very careful in this respect, and it has done it for centuries.

But that is not enough, you also have to analyze how beliefs are accepted. Humanely speaking, there will always be a cut-off point.

There is an interesting anecdote: When Napoleon had already conquered almost all of Europe, he arrested the pope. On a visit to the place where he held him in custody, he said, "I will exterminate your church." The pope laughed. Napoleon asked him, "What are you laughing at?" The Pope answered: if we the members of the church have not been able to end it with our attitudes, much less you " .

The right question for the answer to the original may be: Why has the Catholic Church maintained itself over the centuries?

Greetings from Venezuela

I think, it's not religions that are failing, it's people. Sometimes this means that these people no longer exist, religious wars or wars of other kinds have eradicated them, or in the case of only a small number of members of a religious community they have adapted to other religions. Overall, the phenomenon described that triggers the question is limited. It is much more common that the mixture of ethinc fate (incl. their religious faith) and strong changes in the environment leads to new faith movements, mostly then younger (new) and older (traditional) beliefs become mixed. Therefore, the apparent end of religion is only apparent. New beliefs are emerging. Even atheism, which originated in Europe with the materialists of the 18th century, is not free of clouding and changes. Apparently, people need religious beliefs for one simple reason. They are so intelligent and know: There are questions they can't answer, and there exist worlds in the cosmos they will never reach or experience. So it becomes difficult to live without the idea: If man a beeing of both intelligence and weakness there must be a higher power, a God (or the law of a karma) who manage all things.