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.

Doubtless One

Doubtless One's power and toughness are each equal to the number of Clerics on the battlefield.
Whenever this creature deals damage, you gain that much life.

Ancestor's Prophet

Tap five untapped Clerics you control: You gain 10 life.

Voice of the Blessed

Whenever you gain life, put a +1/+1 counter on this creature.
As long as this creature has four or more +1/+1 counters on it, it has flying and vigilance.
As long as this creature has ten or more +1/+1 counters on it, it has indestructible.

Master Apothecary

Tap an untapped Cleric you control: Prevent the next 2 damage that would be dealt to any target this turn.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Sigarda's Splendor

As this enchantment enters, note your life total.
At the beginning of your upkeep, draw a card if your life total is greater than or equal to the last noted life total for this enchantment. Then note your life total.
Whenever you cast a white spell, you gain 1 life.

Test of Endurance

At the beginning of your upkeep, if you have 50 or more life, you win the game.

Atalya, Samite Master

{X}, {T}: Choose one —
• Prevent the next X damage that would be dealt to target creature this turn. Spend only white mana on X.
• You gain X life. Spend only white mana on X.

Battletide Alchemist

If a source would deal damage to a player, you may prevent X of that damage, where X is the number of Clerics you control.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Soul Warden

Whenever another creature enters, you gain 1 life.

Weathered Wayfarer

{W}, {T}: Search your library for a land card, reveal it, put it into your hand, then shuffle. Activate only if an opponent controls more lands than you.

Plains

Boon Reflection

If you would gain life, you gain twice that much life instead.

Battlefield Medic

{T}: Prevent the next X damage that would be dealt to target creature this turn, where X is the number of Clerics on the battlefield.