If you've read the first two Narnia chronicles, The Lion, the Witch, and the Wardrobe and Prince Caspian, you already know that Aslan, the great Lion who rules Narnia from beyond the sea, is a figurative stand-in for Jesus Christ. In The Voyage of the Dawn Treader, Aslan's Christ-like nature comes out in his different appearances – as Eustace's baptizer and redeemer, as a mystical white Lamb, and as an albatross that looks for a moment like a cross. At the very end of the book, Aslan comes close to explaining who he is and how he relates to Christianity, telling Edmund, Lucy, and Eustace that in their world he has "another name" which they will have to learn (16.76). For more details on the religious symbolism Lewis uses to develop Aslan as a Christ figure, see the "Symbolism, Imagery, Allegory" section.
Aslan makes six appearances in The Voyage of the Dawn Treader, usually just to one person or a very small group of people:
The Aslan in this book has a personal relationship with each of the characters and relates to them individually – which is also connected with his symbolic role, since Christians tend to think of Jesus as a personal savior.
In The Voyage of the Dawn Treader, Aslan inspires fear and awe, especially when people know that they are doing something wrong or that they don't measure up to his standards. When he first sees Aslan, Eustace is in the form of a dragon, but he still feels fear: "I wasn't afraid of it eating me, I was just afraid of it – if you can understand," he says to Edmund (7.34). When Lucy sees Aslan in Coriarkin's magic book, she is already feeling guilty for wanting to make herself beautiful with magic, and the sight of Aslan's face is terrible: "She became horribly afraid" (10.22). But even when he inspires strong feelings, Aslan tries not to give direct orders or instructions. Often his appearance alone is enough to bring people to their senses, such as when Caspian and Edmund realize that their avarice is out of control after seeing Aslan walking on the hillside of Goldwater Island.
At the end of the book, however, everything changes: Aslan is forced to appear to the disobedient Caspian and give him specific instructions about who will go to the end of the world and who will go home. We're tempted to read this as a moment when the plot of the book breaks down: usually we like characters to do what they do because of motivations that have developed over the course of the novel, not because God steps in and tells them what to do. However, one of the points of this book seems to be that, even when they feel like they're exercising free will, the characters are always doing Aslan's bidding.