To be very broad, this deck utilizes Human card synergies on top of functional, practical spells.

Comprehensive Breakdown of this Deck:

Using White and Green cards, this decks power comes from great synergy between all the cards. Specifically, the synergy comes from synergies between Human type cards. Any faults, weak-points, or vulnerabilities of the deck ideally are made up with the use of spells. Here's an extensive review of the part each card in the deck plays:

__CREATURES__

Champion of the Parish: This card has extreme potential to become powerful, just by being there, since it gets a +1/+1 counter for each Human put into play, which automatically makes it so basically any human cards are beneficial to this deck, regardless of any other benefits they provide. The fact that nearly all other creatures are humans means this card is a definite quantity of 4, it's low cost makes it the perfect card to be a frontline soldier who can progress to an overwhelming force.

Bassara Tower Archer: Another Human, but summoned for Green mana which is good considering the Champions of the Parish are also a 4 quantity card in the deck, but summoned with white mana. Bassara Tower Archers are useful because there are actually very few flying creatures in this deck and no flying enchantments, but they have reach so if the opponent has some flying creatures they won't be able to simply bypass the defenses. Also, the Archer has Hexproof, making it perfect for auras as it can't be targeted by opponent spells so they can easily get rid of the auras and the card, as 2 for 1.

Hamlet Captain: The Hamlet Captain is great for obvious reasons, because whenever it attacks or blocks all the other Humans in this deck, which is basically this entire deck, get a bonus of +1/+1. Not much more to it, but for that simple reason this card gets a quantity 4 to maximize those bonuses.

Avacyn's Pilgrim: The Avacyn's Pilgrim's bonus is not so damage/defense orientated, though simply because it's Human it helps in that regard. The Avacyn's Pilgrim is primarily used to increase mana, and the counters it can give is just a sweet bonus.

Fiendslayer Paladin: The Fiendslayer Paladin is plainly cool looking. But other than that, the reason it's in this deck isn't complicated, it's simply a powerful Human card, being a base 2/2 with lifelink and first strike, it's met to be one of the powerful cards, even if for some reason it's unable/currently not benefitting from any of the other synergies.

Angelic Overseer: This card is actually not a Human but still has a synergy with them. It doesn't help the other cards, but receives great boosts from having at least one human which is almost always the case. This card is a pure super fighter, if it gets out there the opponent probably won't win.

Riders of Gavony: Riders of Gavony allow Human cards to be protected by a choosen color. Typically people only play with 1 to 2 colors, so if all 2 of the Riders of Gavony get on the battlefield then odds are the opponent won't be able to touch your cards with any of their creatures.

Fiend Hunter: Fiend Hunters are great because they meet the Human prerequisite for this deck and also they can exile target cards when they come into play, so any troublesome enemies can be dealt with by them, no matter their strength.