Your mana curve is off (too many 2, 4 and 6 drops / not enough 1 drops) and you aren't running a play set (4x) of any card. If you want to make the deck more efficient then a few things should probably change...

For non-creatures I'd cut Silkwrap, Blind Obedience, Hail of Arrows, Angel's Feather and Chaplain's Blessing. Instead of these running 4xJourney to Nowhere and 4xAcolyte's Reward

For land since devotion is an easy sub-theme Nykthos, Shrine to Nyx is almost an auto-include in mono-coloured decks. Also worth consideration is Emeria, The Sky Ruin, Drifting Meadow and New Benalia all offer some utility, you probably don't need more than 20 land.

Finally for creatures you have no drop creature, I would suggest 4x Perimeter Captain in that role. To make the space cut Staff of the Sun Magus and 2x Plains. You might want to look at Nyx-Fleece Ram, Hero of Bladehold / Archangel of Tithes (in preference to Aegis Angel) or if you want to spend money - Serra Ascendant!

Soul's Attendant and Soul Warden would be good for this. Also, may I introduce you to a card called Rhox Faithmender? No one plays it (Like, at all) but for certain decks, it's fantastic.

Alhammarret's Archive is a must for this type of deck. Sunbound, Nyx-Fleece Ram, Ajani's Sunstriker, Ordeal of Heliod, all super duper Good! Lastly Aetherflux Reservoir is pretty solid

As the comment before mine said Rhox Faithmender is amazing.

Have you considered adding Crested Sunmare ?

_raeofsunlight, I'm not sure how to make it work, as it's a decent amount of money to get enough to make it worth it and I'm not sure what I would take out to make it work. It's an interesting idea, but I'm not entirely sure Crested Sunmare is the best option

If I were to find a way to put it into this deck, I would likely remove Hail of Arrows or Approach of the Second Sun. You really only need one or two Crested Sunmares at most, it's one of those cards that is a wincon in itself. Soul Warden and Suture Priest are both super underrated as well, especially because soul warden gives you life for all creatures, not just your own.