I found a few methods to alter how alignment-based effects treat you by searching d20pfsrd.com, some of which might be useful to you.
Spell - Imbue with Aura
The clerical spell Imbue with Aura, from Ultimate Magic, allows you to impose your own alignment aura on another creature and have alignment-based effects treat them as that alignment, which would be a way of protecting them from the harmful effects of some alignment-based spells (presumably like those cast by the cleric in question):
You infuse another creature with your divine aura, causing the target to radiate an aura identical to your own clerical aura. The target’s actual alignment is not changed, but spells like detect evil or detect good detect only the aura, not the creature’s actual alignment. For the duration of this spell, effects influenced by the target’s alignment function according to the imposed aura, not the creature’s actual aura.
Class - Envoy of Balance
A 5th level Envoy of Balance, from PPC: Champions of Balance, has the Ethical Paradox (Su) class feature, which prevents them from triggering alignment or faith-based sensors and counts them as the most favourable alignment when they are hit by harmful effects:
At 5th level, an envoy of balance remains unaffected by effects from spells and magical abilities based on her alignment or faith. She doesn’t trigger glyphs, symbols, magical traps, or magical sensors set to activate based on a creature’s alignment or religion.
She counts as the most favorable alignment or faith for the purposes of any harmful effects these alignment– or faith-based spells or abilities may have, but doesn’t gain benefits these effects might grant those of a particular alignment or faith unless she is actually of that alignment or faith.
This prestige class does require you to be true neutral to begin with, though, and it's obviously a significant investment.
Feat - Muddled Morals
The Muddled Morals feat from PCS: Inner Sea Taverns offers a saving throw bonus against alignment-based effects, and allows you to treat your effective alignment as one step away from what it actually is when you get drunk:
Benefit(s): You gain a +2 bonus on saving throws against effects that affect you based on your alignment. In addition, choose an alignment one step away from your true alignment; when you are drunk (or worse), spells and other effects affect you as if this alignment were your alignment.
Arcane Discovery - Beyond Morality
The Beyond Morality arcane discovery from PPC: Champions of Balance allows a neutral wizard to be arbitrarily treated as a more favourable alignment when resolving alignment-based spells:
Benefit(s): As long as you are neutral, you may choose to be treated as the most favorable alignment when affected by spells whose effects vary based on alignment (such as holy word). If you are neutral in relation to evil and good, you may choose to be treated as good or evil. If you are neutral in relation to chaos and law, you may choose to be treated as lawful or chaotic. You may only choose to be treated as one alignment type along a single axis at a time (for instance, if you were within the area of both a magic circle against evil spell and an unholy blight spell, you would have to choose to be either evil, good, or neutral for the purpose of determining the spells’ effects).
I think the intended reading of this is that a neutral good wizard, for instance, could choose to be considered lawful good or chaotic good at any given time, but a true neutral wizard could present as any alignment combination. Note that, as written, this ability only applies to spells rather than any other effect which keys off your alignment - that might be deliberate or it might be an oversight in the wording.