I took this to FNM without Athreos, and, funnily enough (albeit in the casual flight, where less prizes are given out and the deck standards are lower) I went 4-0, a first for me with any deck. The cherry on the cake was pulling an Athreos in my prize booster!
I went 2-1 vs Selesyna/Monogreen-splash-white with Voice of Resurgence against a friend, whom I beat reasonably. Game 1 was rough, with me going to 5 cards and him hitting all his creatures in more or less perfect tempo based play. Game 2 I won with Master of the Feast; game 3 was me shutting down the tempo and devotion with Banisher Priest and Banishing Light.
Round 2 was against Rakdos aggro, which I was able to hose pretty decently with early blockers and removal solutions like the above - his deck wasn't very good though, and had little removal.
Round 3 was against a first-timer playing with essentially an intro deck - needless to say that, too, was hosed. I felt bad so I helped him out with his blockers during the second game, and recommended some cards after offering to look through his deck.
Round 4 was a sick matchup, Azorius weenies with Brimaz, King of Oreskos, Precinct Captain, Detention Sphere, Supreme Verdict, and other gross cards. We traded games with manascrew on both sides; game 3 was much closer. We traded evenly in the early game until I got out a Whip of Erebos which swung the life totals in my favour. He d-sphere'd a Banisher Priest and a Xathrid Necromancer which was irritating and gave him loads of devotion, bringing Ephara, God of the Polis online next turn. Luckily I pulled a clutch Celestial Flare as she attacked, taking her out and ending the game as I kept whipping things back in from the graveyard.
Overall I'd say the deck will function much better with Athreos, God of Passage in it (obviously); I also might drop the numbers of Banisher Priest for something more permanent as spiderfingers86 has suggested.
