In Path of Exile, "Holy" skills typically refer to an archetype of spells and attacks used by the Templar class, often dealing Physical and Lightning damage with a focus on conversion and holy-themed visual effects.

New Holy Skills (3.28 Mirage)

The following skills were recently added or significantly overhauled in the Mirage expansion:

• Added a new Strength/Intelligence Skill Gem, Divine Blast: Project a beam of holy light from your shield to a targeted location, causing an implosion of holy energy. This energy then lingers for a short duration, before blasting outwards in a larger and more damaging explosion.
• Added a new Strength/Intelligence Skill Gem, Holy Hammers: Slam the ground ahead of you, calling down a Holy Hammer from above. On hitting an enemy, another Hammer will cascade forward, repeating if further enemies are hit, up to a cap. A Power Charge can be expended to call down additional Hammers to either side of the initial slam. Requires a Mace or Staff.
• Added a new Strength/Intelligence Skill Gem, Holy Strike: Infuse your weapon with holy energy and swing. Successfully hitting an enemy will summon forth a Holy Armament, which copies your main hand weapon stats to determine its own. These Holy Armaments are undamageable minions, and will attack the enemies you target with Holy Strike. Requires a Mace, Sceptre or Staff.
• Added a new Strength/Intelligence Skill Gem, Shield of Light: Retaliate against a blocked hit with a sweep of your Shield, unleashing a wave of light in a cone in front of you. Additional waves also emanate from allies in a radius around the first target struck, towards that target.
• Added a new Strength Transfigured Skill Gem, Shockwave Totem of Authority: Summons a totem that shakes the earth around you, damaging enemies.
• Added a new Strength/Intelligence Transfigured Skill Gem, Static Strike of Gathering Lightning: Attack with a melee weapon, gaining a Gathering Lightning buff for a duration if you hit an enemy. While you have Gathering Lightning, attacks with this skill will cause chaining beams of lightning, which chain farther the more Gathering Lightning you have.
• Added a new Dexterity Transfigured Skill Gem, Charged Dash of Projection: Channel to project an illusion which you steer. You gain stages while it moves, until it stops at a maximum total distance. Waves of area damage frequently pulse along its path, based on your attack speed. Stop channelling to release the illusion, dealing a final wave of damage. Requires a Melee Weapon.
• Sweep: Has been reworked, and is now called Holy Sweep. Holy Sweep swings a two handed mace or a staff in a circle, calling down Holy Hammers to land randomly on a number of enemies struck. Hits from these Holy Hammers cannot be evaded.

Classic Holy-Themed Skills

Before the 3.28 expansion, these skills were considered the core of the "holy" playstyle:

• Summon Holy Relic: Summons a minion that triggers a Physical damage nova whenever you hit an enemy with an attack. It also provides life regeneration to allies.
• Holy Flame Totem: A channeling totem that fires a stream of holy fire, creating Consecrated Ground while active.
• Purifying Flame: A physical spell that creates a wave of fire and Consecrated Ground upon impact.
• Divine Ire: A channeling spell that builds up energy before releasing a powerful beam of holy light (Physical/Lightning damage).
• Absolution: Strikes an enemy with lightning; if they die shortly after, it summons a Sentinel of Absolution that casts its own version of the spell.
• Smite: An attack that strikes a target with lightning and provides a temporary aura that adds flat lightning damage to you and your allies.