Signing up as a Healing Class does not mean that a paladin has to go far down Holy tree; some paladins who fight the Arena player vs. player have tried to combine Holy and ret and it is performing well for them. However, in the Pally talent tree I focuses on is the healing/Protection build.

In the event that you’re ever fighting with a party with a talented Holy Paladin, I’m sure you have figured how bothersome plus it’s difficult to defeat him.
Healing Spec

Spiritual Focus: a pvper is are going to cast Holy Light often, so this is very practical.
Healing Light: increases your spell power.
Pure of Heart: another spell to use against Warlocks
Divine Intellect This becomes necessary.
Aura Mastery: the anti silencing effects; nice since you are nothing without your spells.

Sanctified Light: a percentage to bolster your healing with your attack.
Illumination: a different mana talent.
Unyielding Faith: useful when fighting Warlocks.
Improved Concentration Aura: reduces duration of Interrupt.
Divine Favor: at any time you want better heals or offense.
Holy Power: another gain chance to your Holy spells.
Holy Shock: instantaneous dmg for an enemy with heals for your teammates.
Light’s Grace: Useful in emergency situations.
Holy Guidance: increase paladin’sspellpower.
Divine Illumination: useful when you are going cast a spell which costs a lot of mana like as Beacon of Light.
A healing pally talent spec provides many strategies to keep you and the teammates safe; do not just stick to the holy spells to keep your team from dying, cast other spells like Hand of Sacrifice.

If you play the skills correctly, you is able to keep the party’s survivability and aid your party in beating the opposing allegiance.
Using Hand of Sacrifice keeps you from being in that sticky situation. In the case that the situation gets dangerous, use Beacon of Light on yourself then use holy spells on your group members.

variousDifferent Paladin arena manuals focus on different playstyles, still I think Holy Paladin holds a more valuable part in battlegrounds than the one who focused on damage dealing. Other Holy Paladin Build can be seen here.