In addition to healing dutiesThe Cleric is mainly a martial combatant, using specialized attacks and spells that will augment his damage and accuracy. He can also choose to use spells to damage and debuff his opponents.
Sometimes you'll want your cleric in melee, and sometimes he'll be out of mana and need to engage anyway. We're trying not to have situations where one class does only one thing and then disengages, rests, gets bored, etc. when doing that one thing isn't appropriate or impossible because mana or stamina or some such is used up.
Source: Aradune Mithara