Wrath of God resets a creature-heavy battlefield for four mana, destroying all creatures and preventing regeneration from saving them. It gives white control and midrange decks a dependable way to recover when opponents develop more creatures than individual removal can handle. The straightforward cost is especially useful when you need a sweeper before more expensive defensive spells become available.
Planeswalkers and noncreature engines help you rebuild from a favorable position. Elspeth, Sun's Champion can remain on the battlefield and create Soldiers afterward, while a noncreature enchantment such as Smothering Tithe can keep supplying resources. Decks that rely on a small number of durable engines often benefit more from Wrath than lists trying to maintain a large creature board of their own.
Indestructible creatures survive destruction, so Avacyn, Angel of Hope can make the spell much more favorable for you. Ordinary death triggers still happen for creatures that actually die, which means opponents with Blood Artist effects or powerful graveyard engines may receive value even as their boards disappear. Exile-based removal may be preferable when those death triggers are the larger problem.
The key decision is when to stop waiting for more value. Removing two dangerous creatures can be correct if another combat would put you out of the game. Keep enough resources in hand to follow the reset, and judge the result by the position you create afterward rather than simply the number of creatures destroyed.
