Wisdom is worthless. The game is indeed made so that you can beat anything that's lower level than you, basically. However, if you put your points right, you can beat things two levels above you with no trouble. Of course, if you load up on wisdom and mindread, you're hardly going to cut through butter. But skills do matter. If you put them where they should be.
For instance, instead of putting 15 points in wisdom, put 3 points in summon demon or something
MUCH better. Summoning is overpowered in this game. So is regen stacking & itemization. With enough regen and high armor rating, you don't need any healing. In general, priest skills are quite insane. Good thing this is a pve game, because pvp everyone would be a priest. It's just too easy.
I can't believe mages are actually complaining about balance in this game. If you're not playing on hard, this should be a breeze for your class. It was easy for me as a warrior, and warriors are worthless compared to magic users.