Why Raw? Becasue raw honey is still rich in natural enzymes.
When we take our children to visit Mr. Eiden for our home-school field trips, he lets the children watch as they cut the caps off the honey-comb and spin the combs! He explains that in order for honey to be "ready" for harvest, they have to wait until the bees cap off the honey in the comb...it is then, he says, that we know the honey is below 18% moisture.
He explains furthur; that bees are so clever, they know when the honey has been fanned long enough by their little wings and is ready to be capped for long term storage!
When raw honey is properly harvested it will keep indefinitly! Because no bacteria can grow in honey with low moisture content.
In today's world, honey is so often harvested early, before the bees have had a chance to "dry" it down, due to impatience from the farmer in a rush to bring his product to market.. ...which is why pastuization is necessary under industry standards.