Oracle Text

Exile target enchantment. If the exiled card is a God card, search its controller's graveyard, hand, and library for any number of cards with the same name as that card and exile them, then that player shuffles their library.

Card Rulings

4/26/2014 Deicide looks at the card in exile, not the permanent that was exiled, to determine if it is a God. For each of the Gods in the Theros block, it won’t matter what your devotion to its color(s) was. The card is a God card when not on the battlefield.
4/26/2014 When you search the target’s controller’s graveyard, hand, and library, you may leave any cards with that name in the zones they’re in. You don’t have to exile them.