Inspired by the topic about healing lich.
In my humble opinion, temples should differ much from what they are now. That's how I see it:
A temple is not a cell, but a small (5x5 for instance) piece of city area where you really feel the presence of Gods. Upon entering the temple of your proper alignment you receive a considerable bonus, which you lose again upon leaving the temple. It looks like a spell that grants you saves, armor class, health, mana and moves regeneration. Also it provides hitroll and damroll if you have dual wield skill, or health and mana, if you haven't.
In addition, it adds protection evil or protection good (depending on the alignment of the Temple). Neutrality temple adds some other bonus to the followers. Calm mind, for instance, or some other considerable thing.
It could be like this:
As you enter the sacred grounds of your temple, you feel yourself guarded by Gods of Light.
...
The blessing of Light fades slowly as you leave the temple.
Also, undead of any kind are harshly burned whilst roaming any temple of goodness. Somewhat like >>> ANNIHILATE<<< per round, checking protection good, shroud and reflex saving throw. For an equipped lich with protection good it will remain quite painful anyway (DISMEMBER per round).
Liches, deathknights, necromancers and Chemosh priests will think twice or thrice on entering the temples of Light that way.
Gods of Light send forth waves of white flames to exorcize the foul undead!
The divine retribution >>> ANNIHILATES <<< a mummy of Medagar!
The divine retribution >>> ANNIHILATES <<< a mummy of Medagar!
The divine retribution *** DEVASTATES *** a mummy of Medagar!
The divine retribution >>> ANNIHILATES <<< a mummy of Medagar!
The divine retribution === OBLITERATES === a mummy of Medagar!
The divine retribution >>> ANNIHILATES <<< the zombie of Lorac, King of Elves!
The divine retribution *** DEVASTATES *** the dracolich of a shadow dragon!
The divine retribution MASSACRES Narin!
Perhaps we'll see all living, including evils, hiding in the light temple whilst a lich is prowling city's streets.
Some variations can be invented. For example, the blessing becomes weaker during night for Light temple (during day for Darkness one). Also the holy fires could burn undead less fiercely at night hours.
And, of course, healers at the temples should serve only the ones of proper alignment.