Yeah it doesn't raise your Magic ability...for example, the prayer "Incredible Reflexes" raises your attack by 15%, and if you had 68 attack or something and wanted to wield a Whip, you wouldn't be able too. :P
Complete the Creature of Fenkenstrain quest if you haven't done so already, and use the experiments in the dungeon there. You would want to try to use Iron Knives, but anything works really.