Echoes of Heaven
When the original third of the Host fell, the Dwarves stood up and to offered fight. God smiled upon this sacrifice and rewarded the Dwarves with the Divine Spark, a flame of divinity carried within their hearts to aid them in battling evil. All Dwarves, regardless of sex and station, set aside their lives and took up arms whenever the Fallen threatened, and because of this Dwarves, to this day, are born with the Divine Spark. The only exceptions are the Fallen Dwarves, a race so tainted by sin their Divine Spark has vanished.
The Humans and Elves volunteered next, but only the bravest and noblest of these races volunteered. Unlike the Dwarves, Humans and Elves didn’t stop their entire society when the Fallen approached, and so only certain members of the races received the Spark. To this day, all High Men and High Elves carry the inner flame.
Bearers of the Divine Spark tend to be larger than other members of their race and their physical attributes are closer to the racial ideal. High Men are stronger than Common Men, but High Elves are faster than other Elves. As all Dwarves carry the Divine Spark (or the evil counterpart), there is nothing with which to compare them within their own race, but it is assumed they are more Dwarven than Pre-Fall Dwarves. Having the gift of the Divine Spark does not mean the mortal will actually accomplish great things, but great things tend to be accomplished by those with the Divine Spark.
A person can lose their Divine Spark by committing enough evil acts. When a person loses his Divine Spark, the body sinks, the traits wane. The presence of the Divine Spark might not prove anything, but its loss tells quite the story of sin.
Of final note is the Infernal Taint. Whereas the Divine Spark is the same spiritual essence carried by an angel (although toned down), the Infernal Taint is the essence of a Demon. Fallen races all have Infernal Taint. Likewise, when the forces of Hell detect when someone has lost their Divine Spark, they will frequently approach these fallen with an offer to receive the Infernal Taint. Infernal Taint have similar physical effects as the Divine Spark.
In game terms, any character starting with a Divine Spark (or NPC starting with the Infernal Taint) can be generated using 20 Ability Score Points (rather than the standard 15).