Linden, the Steadfast Queen

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever a white creature you control attacks, you gain 1 life.

War Report

You gain life equal to the number of creatures on the battlefield plus the number of artifacts on the battlefield.

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.

Invoke the Divine

Destroy target artifact or enchantment. You gain 4 life.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Nyx-Fleece Ram

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

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice Fountain of Renewal: Draw a card.

Riot Control

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

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Ajani's Mantra

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

Angel's Feather

Whenever a player casts a white spell, you may gain 1 life.

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform Chalice of Life.

Chalice of Life // Chalice of Death

Plains

Ajani, Wise Counselor

+2: You gain 1 life for each creature you control.
−3: Creatures you control get +2/+2 until end of turn.
−9: Put X +1/+1 counters on target creature, where X is your life total.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Sunbond

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

Daybreak Chaplain

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

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Ajani's Pridemate

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

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.

Seraph of Dawn

Dazzling Reflection

You gain life equal to target creature's power. The next time that creature would deal damage this turn, prevent that damage.

Golden Urn

At the beginning of your upkeep, you may put a charge counter on Golden Urn.
{T}, Sacrifice Golden Urn: You gain life equal to the number of charge counters on Golden Urn.

Aerial Responder

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.

Spirit Loop

Enchant creature you control
Whenever enchanted creature deals damage, you gain that much life.
When Spirit Loop is put into a graveyard from the battlefield, return Spirit Loop to its owner's hand.