4 Light from Within

4 Hearthfire Hobgoblin
4 Benalish Marshal
2 Fiend Hunter

4 Consul's Lieutenant
4 Knight of the White Orchid
2 Anafenza, Kin-Tree Spirit
4 Kor Aeronaut
4 Knight of Meadowgrain
4 Acolyte's Reward

4 Shefet Dunes
4 Memorial to Glory (Not a super-great fit, but we don't have neither 1-drops nor 5-drops)
4 Windbrisk Heights
12 Plains

Sideboard
4 Selfless Spirit
3 Inquisitor Exarch
4 Jotun Grunt
4 Ethersworn Canonist
4 Palace Jailer

First and foremost the main deck is only 58 cards (36 spells and 22 lands).

Lack of removal is going to bite you hard. Could I recommend Fiend Hunter at least? Unmake or Crib Swap are non-creature options to just get things gone.
Note that with the way Acolyte's Reward is worded it only does damage equal to the amount prevented, not necessarily the full X (Devotion to White count).

Beyond that the deck doesn't seem to need help in particular, but I can still offer my opinions and/or thoughts on other ways you could take it.

Value Oriented:
Sun Titan as a curve topper, because dumb card is dumb.
Obligatory Weight of Conscience note to combo with Sunny D. Though Oblivion Ring is more catch-all.
Any mono-white deck has me considering Emeria, the Sky Ruin. Maybe not a playset because you look like you want your curve to be low, but the opportunity cost is pretty low(I'm thinking maybe put it in over some Memorial to Glory)

Evasion/top end:
Angel of Jubilation gets and grants more p/t buffs.
Archangel of Tithes makes cracking back difficult for opposing weenie strategies
Nobilis of War will just be absolutely titanic and make you crack for about eleventy billion damage.
Divinity of Pride means just about nothing can race you
Skyhunter Skirmisher super swingy in your deck, either very meh or hits like a truck.
Aerial Responder is probably safer, the floor is much higher and the ceiling is very close to the same imo

Cardflow:
Mentor of the Meek
Bygone Bishop
Wall of Omens

One last thing, I don't have a problem with it in principle, but in practice I've never bothered with a sideboard for a casual deck as it implies a multi-game match where both decks are designed to board against eachother. Personally the people I play with casually don't bother with sideboards so a sideboard for one of my decks seems either unfair or unused. I just put all my tech in the main deck based on my playgroup's tendencies and let the cards fall where they may.

Updated the deck.
Added a bit more removal, brought card count to 60.

I am always glad to see Light from Within

Flyheight's got a point about Aerial Responder and the demigods and those angels too.
I'd run Fiend Hunter over Fairgrounds Warden. That's an extra +1/+1 from Light from Within.
Brave The Elements?
Stasis Snare?
Dawn Elemental in lieu of a 5 drop. Needs Light Within to really shine, but then it's really hard to deal with.
Heliod, God of the Sun would be easy to use. The tokens wouldn't get the LfW bonus, but your other buffs would work.Spear of Heliod would be nice on multiple fronts.