As I have been learning, the magic people speak of is in every person alive. What I mean by magic is the ability to make things happen seemingly from thought.
Some people see magic as spirit, and spirit is in everything wherher you reference it as Holy Spirit (Christianity) or Mother Nature (Pagan,wiccan maybe?). It is in nature, self and everything.
The thought of prayer, to focus your thought on one image betwee one or more people to have a task completed.
To my understanding things are changed due to a common feeling/emotion felt between many and the spirit re-forms to fulfil the task.
When the task is complete people see it as a miracle or a magical event. When really it is a belief that it would happen and belief shaped the world.
If people believed, truely believed that the air they breath would kill them then it probably would.