The battle shows the triumph of good over evil, Christ over Satan, and death over life. We do not need to read too deeply to understand this scene. After all, Lewis is writing first and foremost about Narnia. The Christian allegory is secondary to the main story. The victory of Peter's forces and the murder of the Witch are not important because they stand for the victory of Christianity and the defeat of Satan. More simply, they are important as a victory of good over bad. Lewis suggests that any battle where good triumphs over evil can be symbolic of Christ's victory over Satan.
Although the action of the novel continues through the battle scene, Chapters 16 and 17 comprise the denouement of The Lion, the Witch, and the Wardrobe. The climax of the book really comes when Aslan rises from the dead. The most noteworthy thing that occurs after the climax is Edmund's sudden transformation. Edmund had moved to the side of good after deserting the witch, but it was an uneasy departure. Even Edmund's talk with Aslan, though it had firmly convinced him of the need to stay on Aslan's side, hadn't been able to remove his lingering sense of guilt and doubt. Now, however, Edmund has fought his own battle and redeemed himself with his own hand. Ultimately, this is as important as Aslan's self-sacrifice to save Edmund. A person cannot be simply carried through life into enlightenment and salvation, but must strive to achieve these goals through his or her own efforts. Human effort is as important as divine intercession. Edmund realizes that he must prove his worthiness and risks his own life to smash the Witch's wand. When Aslan knights Edmund, it is a sign that Edmund has atoned for his sins and can now look upon the world without fear or shame.
The Professor makes his second and last appearance at the end of the book, and again he appears wise and knowing, almost to the point of omniscience. The Professor confidently predicts that the children will return to Narnia. We wonder how he can be so sure. It appears that Lewis makes a cameo appearance here, and assures us that he will write more books and bring back the Pevensies for more adventures in the land of Narnia.