This post addresses this subject.
http://forums.projectego.net/skorms-bow-7734/
Joey.nsz does a good job of explaning how to do it. Here is his post:
It all matters on certain points, you will gain more sacrifice points regarding the following points:
- The "better" [good] your allignment, the more sacrifice points you get
- Sacrifice your sacrifices at midnight, earns you more points also
What I personally always do
- Go to the Chapel of Skorm, Teleport to the Witchwood Cullis Gate or Knothole Glade, walk to Temple of Avo, talk to the bodyguard and hire him. Recall back to the Chapel of Skorm when you are sure your bodyguard follows you. After that Teleport to Oakvale and fetch the bodyguard waiting for you at the gates in front of the Memorial Graveyard [map shows a green dot].
Recall to the Chapel of Skorm. Save your World so you can try again later if the amount of points gained do not satisfy yourself. Then sacrifice them.
*I think you need 800 points in TOTAL before you get Skorm's Bow [you can do this as many times as you want to since the guards respawn after a certain amount of time*
I use those 2 guards because they have a "good allignment bar". I think sacrificing the "good" guards gains you more points than when sacrificing the "evil" guards.