Ineed writing an epic poem about fire

Do you want examples of specific types of poems? Or just a poem you want to create? If it's the first I would suggest you create a Free Verse Poem. 

Epics generally contain stories about heroes that embody civilization as a whole(such as Hercules). Others speak of divine human intervention. If this one is to be about fire, you would need to talk of fire in this manner. It is possible to speak of fire in a metaphorical way, rather than a literal one. For instance, saying, "The great fire raged across the land, burning everything in its path," would probably work, but it limits your options. Saying, "The fire raged in the man's heart, turning him into a beast that battled his way to victory," speaks in a metaphorical manner and probably allows more options.