So here is my lore question,
In Wow lore, mages are those who study and learn how to use/control magic be it Frost, Fire, and Arcane. In Wow lore, Priests are those who study the light and learn how to use/control it. During times of war/crisis magi and priests both use their powers to help/protect others.
So is the light another type of magic?
Both the light and arcane/fire/ice take time to study in order to use it effectively. Both the light and fire magic are searing when used on others. Both the light and the arcane are linked to the titans.
The dark side of both the light and arcane/fire/ice is shadow magic. A warlock that uses shadow magic can control demons, a priest that uses shadow magic can control minds.
What if the light isn't a faith but another cosmic force that can be used if the person has enough will to control it. This would explain why others like the scarlet crusade can control the light even though their faith is corrupted. However how can the light abandon people ? Let us look at magic. Magic takes focus to control. So instead of the light abandoning them what if they simply lost the focus needed to control the magic.
This is my theory.