Phosphorous matches were invented in the 18th century.
Before that time, how did people light fires? They rubbed two sticks together (tedious), or they used a bow drill (also tedious), or, if they were lucky, they had flint and steel at their disposal, and they could throw sparks in the general direction of something flammable, hoping it would catch fire (not useful for lighting candles.)
But, for the most part, the fires people made were lit from a coal out of yesterday's fire, for, if you banked the coal all night by covering it with ash, the embers would be ready to light a new fire come the dawn. It was a great embarrassment for a family to have to beg a burning coal off their neighbors, because letting the fire go out looked lazy and careless. The fires people had were, essentially, always burning, however low.
This has been going on since we discovered fire. Before any fancy-shmancy things like flint or bow drills, the only way people could be sure to always have fire was to keep it going. There's a cave in China where neolithic people lived for thousands of years, before finally being forced out by the size of the ash pile.
In that sense, the story of humanity is the story of an eternal flame — carried to new lands, sputtering in the cold wind, but never dying. In one form or another, there's a fire that's been burning ever since that fateful lightning strike (or Prometheus, if you prefer) brought humans a tool that would forever change their bodies, their souls, and eventually, the whole world.
You'd think fire would have been supplanted by electicity now. For most of our daily tasks, it has; we are not as close to fire as we used to be. But most of the electricity that powers your fancy space heater comes from coal-fired power plants! The flame has not yet gone out, however distanced we are from it.
May it never go out. May we never go out.
Here's to the eternal flame!