Beloved Princess

Lifelink
Beloved Princess can't be blocked by creatures with power 3 or greater.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

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.

Impassioned Orator

Whenever another creature you control enters, you gain 1 life.

Fight as One

Choose one or both —
• Target Human creature you control gets +1/+1 and gains indestructible until end of turn.
• Target non-Human creature you control gets +1/+1 and gains indestructible until end of turn.

Light of Promise

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

Healer's Hawk

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

Banishing Light

When Banishing Light enters, exile target nonland permanent an opponent controls until Banishing Light leaves the battlefield.

Hunted Witness

When Hunted Witness dies, create a 1/1 white Soldier creature token with lifelink.

Plains

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Linden, the Steadfast Queen

Vigilance
Whenever a white creature you control attacks, you gain 1 life.

Healer's Flock

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.