The following text should be taken with a pinch of salt.
Die vile Mage! I shall remove your presence from the face of the- *URK!*
Sadly, Kimber the Blessed failed to finish his speech as he got hit by a Spell Trigger filled with 3 Lower Resistances and a Chain Contingency filled with 3 Abi-Dalzim's Horrid Wiltings.
Okay, back to a more serious note. I have nothing against Clerics and I know that they can be very powerful. Heck, you can even make them even more powerful by dualling to a Cleric from a Fighter. I like Clerics, and I try to use them whenever I can if I am playing a party. Multiclassed Cleric/Mages totally rock and you can try it out by using Aerie.

I love Aerie, and I have experimented spell combos with her before.
Clerics are powerful.
Mages are very powerful.
Multiclassed Cleric/Mages are...