Milton's Messiah provides the first comprehensive book-length analysis of the nature and significance of the Son of God in Milton's poetry and theology. The book engages with Biblical and Patristic theology, Reformation and post-Reformation thought, and the original Latin of the treatise De Doctrina Christiana, to argue for a radical reassessment of Milton's doctrine of the atonement and its importance for understanding Milton's poetics. In the footsteps of Dennis Danielson's Milton's Good God, this study responds to William Empson's celebrated portrayal of Milton's God as a deity invoking dread and awe, and instead locates the ultimately affirming presence of mercy, grace, and charity in Milton's epic vision. Challenging the attribution of an Arian or Socinian model to Milton's conception of the Son, this interdisciplinary interpretation marshals theological, philological, philosophical, and literary-critical methods to establish, for the first time, not only the centrality of the Son and his salvific office for Milton's oeuvre, but also the variety of ways in which the Son's restorative influence is mediated through the scenes, characters, actions, and utterances of Paradise Lost and Paradise Regain'd. From the allegorical sites Satan encounters as he voyages through the cosmos, to Eve's first taste of the Forbidden Fruit, to the incarnate Son's perilous situation poised atop the Temple pinnacle, Hillier illustrates how a redemptive poetics upholds Milton's proclaimed purpose to assert eternal providence and justify God's ways. This original study should court debate and controversy alike over Milton's priorities as a poet and a religious thinker.