Zealot the worst performer compared to gear ?.

My Zealer doesn't use Fanaticism, but does decent damage with amazing survivability. The gear:

Guillaume's Face Helm
Gore Rider Boots
Guardian Angel armor
Azurewrath Phaseblade
Herald Of Zakarum shield
Verdungo's Hearty Cord Belt
Venom Grip gloves (can be replaced with IAS glove if struggling with breakpoints)
Highlord's Wrath ammy
Carrion Wind ring
Raven Frost ring

Skills:
20 Zeal
20 Conviction
20 Holy Shield
10 each resist aura (passive max resist)
1 point wonder: Redemption

Act 2 merc with Holy Freeze:
Reaper's Toll
Blackhorn's Face
Treachery

Conviction boosts cold damage of Azurewrath and merc, negates other Conviction auras and reduces defense.

I have 3 sources of damage: Physical (with 50% Crushing Blow), Magic and Cold.

It might not trample enemies like a Zealer with Grief and Fanaticism, but it's a pretty safe and fun build. I go to Ubers without trouble with him, and sometimes I don't even drink potions.

Worth mentioning the build doesn't require runewords (except for the cheap Treachery), so if you're playing online you can trade them away. The downside is having to socket every piece of gear, which requires 6 Larzuk quests in total (the merc's gear is optional, but obviously desired). So, prepare to trade those unique items with sockets or do some Larzuk runs yourself.