The undead are endless in (and near) the Ruins of Andorhal, and as a paladin, you have abilities granted to you by the Light specifically to defeat the undead. It is never easy, defeating the undead, but it is easier for you than for many others. In little time, you have collected a sufficient bag of the scourge stones.
The High Priest warns you that dispelling the evil from the stones is likely to attract undead from quite a ways away.
Having driven the Evil from these particular scourgestones, High Priest Thel'danis asks you to return the now-inert scourgestones back to Commander Valorfist.
The commander is impressed, and decides to reveal more of his plan to you.
The commander's plan is to use the scourgestones as a weapon against the undead hordes. But forging such a weapon requires a particularly rare sort of magic, that can only be found in one place: The Temple of Atal'Hakkar. 6 Troll leaders each carry a voodoo feather. Your job: collect the set.
Your adventures to the temple, then within its precincts, are long and arduous. But you prevail! You return with the coveted feathers. The commander bestows upon you a Holy Mightstone, fruit of your labors.