Fundamentalists of many different shades- both religious and philosophical- see themselves in a grand battle between good and evil. They believe the Earth can only be saved by vanquishing evil (those who don't share, or who actively oppose, their beliefs) or by converting everyone to their beliefs. We see this amongst those who subscribe to scientific materialism. They believe they are on a quest to rid the human race of irrational beliefs that are holding us back from the glorious advancement that would be possible if only we could be rational, for once!
Another example of fundamentalism resulting in an epic drama is found among "communists". They believe the only way for the human race to advance is to throw off the shackles of capitalism and the elites who rule through it. Of course, this ignores the fact that elites have used many social and economic systems to rule throughout history, including communism itself.
In recent times it seems the most virulent and dangerous brand of fundamentalism has been found among those who classify themselves as "Muslims"- followers of the teachings of Muhammad and his book, The Quran. Although the vast majority of Muslims seem to be peaceful there is a small and vocal minority that has the goal to have their beliefs take over the world, or at least certain portions of it. To this end they seek the take over of legal systems by what is known as "Sharia Law". Certain groups are even willing to kill to achieve this aim.
Another group, Christian fundamentalists, do not generally seek to take over the world by force. Instead, they was waiting for the re-emergence of their messiah to herald a new age where non-believers are judged and punished and believers are rewarded for their steadfastness.
In all the above cases we can see that those who hold to these fundamentalist positions believe they are part of the select few who are either doing God's will, or are at least acting rationally for the benefit of mankind (in the case of materialists). They see themselves in active opposition to people holding different beliefs, who they view as a hindrance to the development of God's kingdom on Earth.
This belief in an epic drama results in such people focusing their attention on fighting or attempting to change other people. As a result, they ignore the log in their own eye whilst pointing out the mote in others' eyes (Matthew 7:4). Consequently, they stagnate in their personal growth and do not grow towards God as we are each designed to do. Only when these epic dramas are seen as the illusory ego games that they are, is it possible for us to continue on our path of growth in consciousness.
See also: Freedom from Ego Dramas by Kim Michaels