Faith's Shield

Target permanent you control gains protection from the color of your choice until end of turn.
Fateful hour — If you have 5 or less life, instead you and each permanent you control gain protection from the color of your choice until end of turn.

Ivory Cup

Whenever a player casts a white spell, you may pay {1}. If you do, you gain 1 life.

Charmed Stray

Lifelink
When Charmed Stray enters, put a +1/+1 counter on each other creature you control named Charmed Stray.

Apothecary Initiate

Condemn

Put target attacking creature on the bottom of its owner's library. Its controller gains life equal to its toughness.

Healer's Hawk

Alseid of Life's Bounty

Lifelink
{1}, Sacrifice Alseid of Life's Bounty: Target creature or enchantment you control gains protection from the color of your choice until end of turn.

Hopeful Eidolon

Bestow {3}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Enchanted creature gets +1/+1 and has lifelink.

Trelasarra, Moon Dancer

Whenever you gain life, put a +1/+1 counter on Trelasarra, Moon Dancer and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ajani's Welcome

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

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Children of Korlis

Sacrifice Children of Korlis: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Fountain of Renewal

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

Hunted Witness

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

Court Cleric

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Court Cleric gets +1/+1 as long as you control an Ajani planeswalker.

Jaddi Offshoot

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

Haazda Marshal

Whenever Haazda Marshal and at least two other creatures attack, create a 1/1 white Soldier creature token with lifelink.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Arcbound Mouser

Lifelink
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Anointed Chorister

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
{4}{W}: Anointed Chorister gets +3/+3 until end of turn.