Religions spread a the speed of the communications available. His lifetime is variable. In the past, sectarian movements limited themselves to reduced circles, if not reduced to a single tribe. Naturally, when communications are slow, a crazy religion, that says, for examole, that cooking food is bad, he lives and dies (by malnutrition of the believers) in a reduced space.
But this is no longer the case. With the invention of the newspapers, but specially the radio, sectarian movements spread trough all the earth almost instantly . from the XVII century on, communists experiments. by protestant sects, where essayed repeatedly and failed. Most of them without notice, They did not had such a propaganda tools like the radio and the newspapers. Modern communists in the early XX century had. As well as Hitler in Germany. These instant religions burned the stages of their crazy ideas (crazy because they where against reality, like the prohibition of cooking food) at the rapid pace that one would have expected if they have been reduced to a little commmunity, but their disastrous impact for the world were much much greater. In fact the invention of the press, the linotype, the radio, the TV and internet are followed by the corresponding religions and ideologies that spread at the speed permitted by their new communication means.
We are exposed more than ever to these instant religions. People can not live without orienting his life towards a goal beyond itself, that is, that transcend itself in a comunity with others that share the same goals. He need to feel the warm of the others that think like him (that is almost a theorem of evolutionary game theory applied to social entities).
The community is made around a plan for the future, an organization principles and other elements that is not worth to mention here. These are the set of beliefs that make present by a set of rites and sacrifices, being them small or large. The community sentiment can be reduced to a tribe or the whole Humanity depending on his means of life and the short term-long term orientation.
That is not bad in principle, is what is it and is human nature. But in anomial societies like the modern West, where the small communities have been lost time ago, and the christian faith that created a big sense of community for all the West also has been lost, is not something bearable. That drive many desperate people, fundamentally atheistic or agnostic, to coalesce around whatever crazy idea that a leader or group of leaders tell to him. These crazy ideas take much of the base religion: salvation, apocalypse, priesthood etc. The more the de-christianization, the more desperately people adopt these instant religions.