Want to hear the pure and simple essence of existentialism (couldn't resist the pun)? Read iDeath's writeup about the lowest spiritual common denominator.

Existentialism in a nutshell:
  1. The universe is meaningless and chaotic.
  2. We need meaning and structure in our lives.
  3. We will therefore create this meaning and structure the best we can.

That is existentialism. Substitute 3. with:
3. We will turn to religious teachings as a source of meaning and structure.
And you have most modern religions (as they are practiced) and a number of supposedly secular ideologies.

Remove the rules and replace them with:
1. The universe has a meaning, and a purpose. There is somebody or something in charge.
And you have deep spirituality, and Plato's ideas. Both of which existentialists consider to be a bunch of bunk.

Add to that:
2. We have an inside line to this higher meaning. It is contained in this book/scroll/prophet's head. Literally, not just symbolically.
And you have religions as they were originally concieved, and modern secular/religious fanaticism.


Of course, I can't walk away from this without plugging my own distro. F1r3br4nd's Extistentialism Pro: The Millenial Edition
  1. The universe is meaningless and chaotic.
  2. We need meaning and structure in our lives.
  3. We will therefore create this meaning and structure the best we can.
  4. Because of how our brains are hardwired after millions of years of struggling for survival, there will be common features to the answers we come up with in step 3. Insofar as these answers influence our behavior, they themselves will be subjected to memetic evolutionary pressures. In short, the answers that help us survive will be the ones that catch on in the long run, so we might as well keep this fact in mind when we're thinking about our answers in the first place.