Serra Avatar

Serra Avatar's power and toughness are each equal to your life total.
When Serra Avatar is put into a graveyard from anywhere, shuffle it into its owner's library.

Staff of the Sun Magus

Whenever you cast a white spell or a Plains you control enters, you gain 1 life.

Kemba's Skyguard

Flying
When Kemba's Skyguard enters, you gain 2 life.

Ordeal of Heliod

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Heliod.
When you sacrifice Ordeal of Heliod, you gain 10 life.

Sunspring Expedition

Landfall — Whenever a land enters under your control, you may put a quest counter on Sunspring Expedition.
Remove three quest counters from Sunspring Expedition and sacrifice it: You gain 8 life.

Path of Bravery

As long as your life total is greater than or equal to your starting life total, creatures you control get +1/+1.
Whenever one or more creatures you control attack, you gain life equal to the number of attacking creatures.

Seraph Sanctuary

When Seraph Sanctuary enters, you gain 1 life.
Whenever an Angel you control enters, you gain 1 life.
{T}: Add {C}.

Riot Control

You gain 1 life for each creature your opponents control. Prevent all damage that would be dealt to you this turn.

Kabira Crossroads

Kabira Crossroads enters tapped.
When Kabira Crossroads enters, you gain 2 life.
{T}: Add {W}.

Sunbond

Enchant creature
Enchanted creature has "Whenever you gain life, put that many +1/+1 counters on this creature."

Devout Invocation

Tap any number of untapped creatures you control. Create a 4/4 white Angel creature token with flying for each creature tapped this way.

Congregate

Target player gains 2 life for each creature on the battlefield.

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Ajani's Mantra

At the beginning of your upkeep, you may gain 1 life.

Soul Warden

Whenever another creature enters, you gain 1 life.

Paragon of New Dawns

Other white creatures you control get +1/+1.
{W}, {T}: Another target white creature you control gains vigilance until end of turn. (Attacking doesn't cause it to tap.)

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

Chaplain's Blessing

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Landbind Ritual

You gain 2 life for each Plains you control.

Seraph of the Masses

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying
Seraph of the Masses's power and toughness are each equal to the number of creatures you control.

Pride Guardian

Defender
Whenever Pride Guardian blocks, you gain 3 life.

Oppressive Rays

Enchant creature
Enchanted creature can't attack or block unless its controller pays {3}.
Activated abilities of enchanted creature cost {3} more to activate.

Ajani, Caller of the Pride

+1: Put a +1/+1 counter on up to one target creature.
−3: Target creature gains flying and double strike until end of turn.
−8: Create X 2/2 white Cat creature tokens, where X is your life total.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Plains

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Glimpse the Sun God

Tap X target creatures. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Seraph of Dawn

Goldnight Redeemer

Flying
When Goldnight Redeemer enters, you gain 2 life for each other creature you control.