Paradise Lost
The last and greatest of the classical epics in English. Milton set out to "justify the ways of God to men" and instead created the most compelling villain in literature. Satan's speeches are the poetry of rebellion and wounded pride; the Fall itself is rendered with such empathy that Blake famously declared Milton was "of the Devil's party without knowing it." The poem's blank verse shaped English poetry for two centuries.
Milton's God talks like a defense attorney, and heaven's councils are the dullest rooms in the poem. After Book Four, Satan dwindles from tragic rebel to special-effects serpent. Then Michael spends the last two books narrating a history of the world to Adam, a lecture with visuals. Eve gets blamed throughout, and the Latinate syntax fights you line by line.
The case for it and the rest of the canon open with Pro.
