Dawn of Hope

Whenever you gain life, you may pay {2}. If you do, draw a card.
{3}{W}: Create a 1/1 white Soldier creature token with lifelink.

Prison Realm

When Prison Realm enters, exile target creature or planeswalker an opponent controls until Prison Realm leaves the battlefield.
When Prison Realm enters, scry 1.

Plains

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Leyline of Sanctity

If Leyline of Sanctity is in your opening hand, you may begin the game with it on the battlefield.
You have hexproof. (You can't be the target of spells or abilities your opponents control.)

Linden, the Steadfast Queen

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

Devout Decree

Exile target creature or planeswalker that's black or red. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Leonin Vanguard

At the beginning of combat on your turn, if you control three or more creatures, Leonin Vanguard gets +1/+1 until end of turn and you gain 1 life.

Resplendent Angel

Flying
At the beginning of each end step, if you gained 5 or more life this turn, create a 4/4 white Angel creature token with flying and vigilance.
{3}{W}{W}{W}: Until end of turn, Resplendent Angel gets +2/+2 and gains lifelink.

Ajani's Pridemate

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, Serra Ascendant gets +5/+5 and has flying.

Banishing Light

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

Soul Warden

Whenever another creature enters, you gain 1 life.

Demystify

Ajani's Welcome

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

Cavalier of Dawn

Vigilance
When Cavalier of Dawn enters, destroy up to one target nonland permanent. Its controller creates a 3/3 colorless Golem artifact creature token.
When Cavalier of Dawn dies, return target artifact or enchantment card from your graveyard to your hand.

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.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Heliod, Sun-Crowned

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
Whenever you gain life, put a +1/+1 counter on target creature or enchantment you control.
{1}{W}: Another target creature gains lifelink until end of turn.