Like the bard ability, your allies must be able to see you fight to benefit from this ability.
Ability: Once per day per cleric level, while the cleric is engaged in combat, the cleric can inspire his allies with his fighting prowess. This ability functions similar to the Bards Inspire Courage ability except it grants a +1 morale bonus to Saving throws verses Charm and fear effects and a +1 morale bonus on natural weapon or unarmed attack and damage rolls per 4 cleric levels. So a 5th level cleric would grant a +2 to saves, attack and damage, a 9th level cleric would grant a +3 etc... Like the bard ability, your allies must be able to see you fight to benefit from this ability.