Magic

"Magic is what makes miracles real."   Everyone and everything in this world possess some amount of magic. The question is how much and how will it be used.   The use of magic depends on each individual. Some who possess a lot might use it to cast fire ball or open black holes. Others like warriors who possess a medium amount could use it to bolster their strength or make flashy sword strikes. But even a common civilian possesses some magic. That they could use to help water their fields or cast a simple alarm spell on their wares in case someone would want to steal them.   

History

In history there have been cases of people not possessing any magic at all. Such cases are extremely rare however.