(Combat): Your weapon's good burst effect hit Twilight Giant Rat for 17 points of good damage.
It was getting Immune messages to Holy.
Not really sure what you mean about the way it reads, since it's pretty clear that it affects non-good:
"This weapon is imbued with the power of good and deals 1d6 points of good damage against all of non-good alignment. Additionally, all targets of non-good alignment take an extra 3d6 damage on a critical hit for weapons with a x2 critical multiplier, 4d6 for a x3 multiplier, and 5d6 for a x4 multiplier."