The basic idea is to first put in every useful holy card to have the best chances at the tier 1 passive treasure Divine Illumination. The passive is so good that it's even worth it to play something like Holy Fire instead of Void Shard to get the synergies going. Chaining multiple holy spells via discovery allows this deck to go the distance, and knowing how to work with random discoveries is a big part of the deck's succes.

Early games are won with the classic Embrace the Shadow into Flash Heal and Desperate Prayer combo, which every other card in the deck helps you get to, by either stalling or thinning the deck. 

The starting treasure is the single strongest card in the deck and should be kept in the mulligan against most matchups. Other than that, Twilight Deceptor and Holy Smite are safe keeps, as well as Shadow Visions and Thrive in the Shadows for early plays in slower matchups.