If it has stats, your players will try to kill it."
An adage with a less widespread but equally true corollary: "If your players want to fight it, it needs to have stats." And who do players want to fight most of all? Easy, the strongest, meanest monsters. And in the Forgotten Realms setting, those are gods.
Gods are not meant to be defeated by a single adventuring party: their abilities are guidelines for DMs. However, avatars - their lesser incarnations they can send to the Prime Material Plane - and quasi-deities can provide a Tier 4 showdown that can't be cheesed with flight plus a Forcecage (looking at you, Tarrasque).
This splatbook contains rules and stat blocks for 39 deities and quasi-deities, for a total of 74 new monster stat blocks: 36 creatures with a divine rank (don't throw these at your players - they will kill them) and 37 creatures with a CR of 30 (they may kill your players, but it ought to be a fairer fight). Many of these stat blocks are inspired by the combined lore and monster abilities of previous editions (3.5 in particular), while a few are completely new. Included in the book there are also 33 new magic items.
- from the publisher's blurb