Vega,
The church will forgive _anyone_ their evil nature, if that person changes their ways and steps into the light.
As long as they remain evil, or continue to perform evil-like actions, then the church will try to kill them.
A perfect example of this is Ryvern. While he was an infernal, the church tried to kill him. When he "saw the light", they forgave him and welcomed him back as ally, comrade, and friend. This despite the fact that only hours before he was mindlessly killing them.
Anyway, thats just the way I've seen them operate... And yea, there have been occasions when this hasnt been the case, but they are mortals after all, prone to mistakes and weaknesses.
Caled Tiercel

Penned by my hand on the 1st of Scarlatan, in the year 253 AF.