tnoyce: Make certain that you have purchased arrows. Without ammo, the bow is useless.
If you are referring to the temple level - even with the bow, the enemy in the rafters is a bit frustrating. Still, I think a bow is the only way to deal with them.

celeborn10: Personally I found the bows to be an exercise in frustration, especially when kiting over uneven terrain. They're pretty dang powerful but I'm thinking I'll stick with Druid until Wizard (homing spells mean I don't break things irl). You can always come back later with a better suited character/gear to get all the gold.
Bows are nice for one shotting enemies in the head and stacking eight arrows for OMGWTFROFLMAO damage to shotgun bosses but you have to be able to anticipate those and prepare with its draw time.

Prator: You can do some crazy damage with some of the trick arrows; a direct hit with a bomb arrow does more damage than any other attack in the game, I think, to say nothing of the bonus damage you get from a headshot with a sniper arrow. Otherwise, I concur; bows are tricky to aim properly, and for me they often miss at point-blank range, somehow. Crossbows are much more reliable.