Pious Spellsurge( Complete Divine, p. 87)
You can use the strength of your faith to augment a spell cast at a critical juncture.
Knowledge (religion) 4 ranks,
By spending 2 faith points when you cast a spell, you gain a +1d6 bonus to the DC of any save required to resist the spell or to your caster level for that spell.
When chosen, this feat gives you 4 faith points, and you may earn additional faith points as outlined in the Faith Feats section.