Because people believe in them
In certain belief systems, Lucifer is considered the saint of hell.
Belief systems are what people believe about the world and/or religion. It is the organization and structure of the way a person thinks the world works.
Religions are belief systems created by humans to explain the meaning of life, the universe, and our place in it.
Like all symbols of belief systems it is as strong as your belief in it.
A justifiable true belief.
A school cannot exist without a curriculum and curriculum is the heart of teaching. A strong belief or philosophy is needed for a curriculum to exist.
No, humans do not have 7 lives like the concept of reincarnation in some belief systems. In most belief systems, reincarnation is the belief that a soul is reborn into a new body after death, but the number of lives a soul may have varies and is not limited to 7.
The political belief systems that rose from the Great Depression include the Marxist movement. This movement influenced most of the political systems during this period.
As is true with most belief systems there exist fringe elements, which oftentimes misrepresent the mainline moderate view. Most "moderate" Christians hold to a very rational faith.
There is no single "Native American" religion, there were around 4,000 tribes and just for example the Cherokee had about 23 different systems. If you were to distill all of these belief systems into a single system of belief, then you could say that the goals of the Native American belief system were very much like Buddhist beliefs: to live your life improving yourself, your tribe, and the world around you without causing harm (destroying) to anyone or anything; understanding during your life that you are of the world, not outside of it (the world can exist without you, you cannot exist without it).
they belive in fairies
Confucianism and Taoism