For a Zealot you need to max Zeal, Fanaticism and Sacrifice in that order. The rest can go to Holy Shield. Basically spend points into Zeal until lvl 30, then max Fanaticism, the complete Zeal if you already haven't, and pump Sacrifice last.
I already went for the the Zeal path with, because it had already some points spent in some Defensive auras that are not usable later and a Hammerdin needs 20 more points to be completed.(Blessed Hammer, Concentration, Vigor and Blessed Aim)