Book III opens with a second invocation to his muse, this time addressed to “holy light” (III.1). Milton asks that the heavenly light shine inside him and illuminate his mind with divine knowledge so that he can share this knowledge with his readers.
The scene shifts to Heaven, where God has been watching all of the events in Hell with his Son sitting at his right hand. He sees Satan flying up toward the new Earth and the parents of mankind. At the same time, he sees everything that will happen because of it, perceiving past, present, and future simultaneously. He sees that man will fall, of his own fault, because God gave him free will—yet without that will, man would not be capable of sincere love. Man would merely go through the motions. While it would be just to punish man for his own actions, God determines that he will act primarily out of love and mercy. The Son, full of compassion, praises God for his kindness toward man, but asks how mercy can be given without destroying justice. God answers that a suitable sacrifice must be made: someone worthy must offer to die to pay for man’s sin. The angelic choirs are silent, but the Son immediately offers himself. He will become mortal so that God can yield to Death and conquer Hell. God is overjoyed, even though he will be giving up his son, because he knows that it is good to sacrifice his son for the salvation of the human race, in order for justice and mercy to be served. Those that have faith in the Son will be redeemed, but those who do not accept grace will still be doomed to Hell. The choirs of angels now break into a song of praise extolling the goodness of both Father and Son, which will turn a sorrowful deed into greater glory for both God and man.
The story returns to Satan, who lands on Earth in what is now China. There are not yet any living things there, or any of the works of man that will eventually distract man’s mind from God. At length, Satan sees a high-reaching structure in the distance, an enormous kingly gate in the sky with stairs leading all the way down to Earth. This gate guards Heaven, which was at that time visible from Earth. Flying over to it, Satan climbs up a few steps to get a better view. He sees the new creation in all its glory, but can only feel jealousy. He does not stay put for long, though: he is drawn by the golden sun, hanging above the green and lush land, and flies toward it. There he sees an angel standing on a hill. To deceive him, Satan changes to a cherub, or low-ranking angel. Recognizing the other angel as the Archangel Uriel, Satan approaches and addresses him. Satan claims to have just come down from Heaven, full of curiosity about the new world he has been hearing so much about, and curious about its inhabitants. Satan’s transformation and his speech are so flawless that even Uriel cannot see through the subterfuge. The Archangel is pleased that a young angel is showing so much zeal to find out about the world that God brought out of the Chaos from earth, air, wind and fire. He happily points out the way to Paradise, where Adam lives. After giving his due respects, Satan flies off with dark intentions.
As the narrative of Paradise Lost shifts from its sustained focus on Hell and Satan and begins to present glimpses of Heaven and God, we may feel that the story loses some of the intense interest and appeal that it began with. The discussion in Heaven is moving and theologically interesting, but the parts of the poem treating the evil designs of Satan are written with more potency and rhetorical vigor. The characters in Heaven play a relatively passive role, watching the story unfold, while Satan actively and endlessly devises his evil machinations. Moreover, the sinful, evil characters hold our attention more easily than the pure and virtuous ones. Satan appears to be the active hero, struggling for his personal desires, and God may seem rather dull. These observations, however, are beside the point that Milton hopes to prove to his readers: God’s reason and grace rule the universe and control all of those who live there.
The encounter between Satan and Uriel demonstrates Satan’s capacity for deception and fraud, as he subverts Uriel’s role as a guardian by disguising himself as a cherub. Uriel is unable to recognize Satan in part because he does not believe it possible that Satan would be lurking around. As a devout and virtuous angel, Uriel is unable to recognize evil even when it presents itself right in front of him. Through Satan’s deception of Uriel, Milton shows the significance of the sin of fraud, or hypocrisy. Fraud is an especially damaging sin because it is invisible to others, hurting them in ways they are not even aware of. In the Inferno, Dante maintains that fraud is the worst of all man’s sins. Milton goes almost as far in showing that leading innocent people to evil is much worse than leading yourself to evil.
Milton reveals his own personal theological positions in Book III. Through God’s initial speech, for example, Milton discards the orthodox Calvinist position of predestination. Omniscient God, seeing the fall in the future, says that men cannot blame God for their fate, or for acts of evil or bad luck, insisting that man possesses free will, even though God can foresee what they will do. God’s speech here contradicts the Calvinist belief, held by most of Milton’s fellow Puritans, that the fate of every man’s soul is decided before birth. Milton refuses to abandon his belief in free will, insisting that man must have free will in order to prove his sincere love for God. This balance between free will and virtue is a paradox—man is free to choose, but only truly free when he chooses the good.