Fire, water, earth, air--the traditional four elements.
Fire keeps us warm and cooks out food, but it can also burn us to a crisp. Water is essential to life, but can also drown us. The earth, which provides our sustenance, can also crack open under our feet and swallow us up. And the air, necessary to life, can form itself into powerful spirals and batter us to smithereens.
Then consider automobiles, weapons, elephants, insects, Botox. Everything seems to have a potential for good or evil.