Wall of Hope

Defender (This creature can't attack.)
Whenever Wall of Hope is dealt damage, you gain that much life.

Sunscorch Regent

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Sunscorch Regent and you gain 1 life.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Gift of the Woods

Enchant creature
Whenever enchanted creature blocks or becomes blocked, it gets +0/+3 until end of turn and you gain 1 life.

Plains

Essence Warden

Whenever another creature enters, you gain 1 life.

Angel of Vitality

Flying
If you would gain life, you gain that much life plus 1 instead.
This creature gets +2/+2 as long as you have 25 or more life.

Zebra Unicorn

Whenever Zebra Unicorn deals damage, you gain that much life.

Ballynock Trapper

{T}: Tap target creature.
Whenever you cast a white spell, you may untap Ballynock Trapper.

Jaddi Offshoot

Defender
Landfall — Whenever a land you control enters, you gain 1 life.

Forest

Soul Warden

Dawnglow Infusion

You gain X life if {G} was spent to cast this spell and X life if {W} was spent to cast this spell. (Do both if {G}{W} was spent.)

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Heroes' Reunion

Ajani's Pridemate

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

Captured Sunlight

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
You gain 4 life.

Rune-Tail's Essence

Prevent all damage that would be dealt to creatures you control.

Rune-Tail, Kitsune Ascendant

When you have 30 or more life, flip Rune-Tail, Kitsune Ascendant.

Rune-Tail, Kitsune Ascendant // Rune-Tail's Essence

Felidar Sovereign

Vigilance (Attacking doesn't cause this creature to tap.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your upkeep, if you have 40 or more life, you win the game.

Venerable Monk

When Venerable Monk enters, you gain 2 life.

Nyx-Fleece Ram

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

Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Twinblade Paladin

Whenever you gain life, put a +1/+1 counter on this creature.
As long as you have 25 or more life, this creature has double strike. (It deals both first-strike and regular combat damage.)