Start by taking out the cards that either don't do anything for the deck's stated purpose or aren't very good at what they do. I would remove Spectral Gateguards , card:Iona's Judgment, card:Angel's Mercy, Inspired Charge , card:Terashi's Cry, Greatsword , Sacred Nectar , Call To Serve , and Demystify . That will get you down to 60.

Also, take out all the Terramorphic Expanse and replace them with 2 more Seraph Sanctuary and 2 more Plains , as there's no reason your deck needs them. The actual math behind "deck thinning" doesn't hold up. If you're not using an effect like this for color-fixing, it's only helpful if you're also using it for the shuffle (Brainstorm , card:Sensei's Divining Top, etc.) or for triggering things that care about lands (Steppe Lynx , Plated Geopede , etc.). 24 land is a good number to stay at for now since you're trying to build up to Angel-level mana. If you can get a few copies of Emeria, The Sky Ruin in here, I think your deck might like it.

Keep playing the deck whenever you get the chance, and take mental notes about which cards are actually helpful and which cards don't pull their weight, then you can add more copies of the former and cut the latter. This is a really good start, though.

@RhadamanthusThanks for the feedback!

I see what you mean about the cards you listed in your first paragraph not fitting in with the rest of the deck.

Emeria, The Sky Ruin is definitely something that would be perfect for this deck, thanks for the suggestion. Taking out the Terramorphic Expanse s for additional Seraph Sanctuary and Plains is also definitely a good move.

I appreciate the advice!