Meanwhile, develop your mana base with Rampant Growth and Borderland Ranger, and prolong the game by gaining life. Cathedral Sanctifier can help with that as early as turn 1. Seraph of Dawn's lifelink ability lets you gain life each time it deals damage. Add in the lifegain potential of Scroll of Avacyn, Seraph's Sanctuary, and Goldnight Redeemer, and you can counteract a lot of damage you may have taken.
Once the Angels arrive, the battle plan becomes simple: attack! Serra Angel and Archangel play both offense and defense thanks to the vigilance ability. Voice of the Provinces comes with a friend that can block a counterattack. And Angel of Glory's Rise can resurrect all the Humans that gave their lives for the cause earlier in the game.
Once you've played the deck, you may wish to diversify your collection of Angels. Luckily, the Avacyn Restored set has plenty of amazing choices! Angel of Jubilation; Restoration Angel; and Sigarda, Host of Herons are all stunning. But nothing holds a candle to Avacyn, Angel of Hope, an indestructible 8/8 Angel that makes all your other permanents indestructible too!