A unit's score is analogous to the religious concept of Karma and homologous to a player's score in a game. A unit accumulates a higher score through the actions of their life. The existence, importance, and sources of a unit's score seem to be matter of great debate and disagreement.
Sources of score
Greatness: How great or accomplished a unit is.
Real World References
In games performance can be characterized by a single dimensional score. A higher score is defined to be more desirable. Using game theory this principle can be extended to any activity with well defined, non-conflicting goals.
Some of the most major debates in christian theology have been over what people are judged by.
Faith versus Deeds
The more emotional disagreements have been between whether a person's faith, deeds, or both are essential. More extreme points of view are characterized by the quotes "Faith without deeds is death", and "Your deeds are as dust."
Complexity versus Single dimension
A more abstract aspect of the debate is if a person's "goodness" can actually be reduced to a single dimension. If it can then one with enough knowledge (i.e. God) can equivocate between all qualities. Even if you counted multiple things (like both deeds and faith) and were able to add them that would be one dimension. The compexity argument is that some things aren't comparable and judgment must be more complex then that.