In the Narnia series, the character of Aslan bears many similarities to Jesus Christ:
- worshipped as a god but only the son of a much greater god (the Emperor-over-the-Sea)
- sacrificed for the sake of his people but then resurrected
- very powerful but sometimes taking the form of a lamb
Out of universe, parts of the series were clearly intended as Christian allegory (and there are quotes by Lewis to confirm this). But my question is about in-universe. Some say that Aslan is actually the same person as Jesus, taking the form of a lion when in the world of Narnia.
The most relevant quote I've found is the following:
"Dearest," said Aslan very gently, "you and your brother will never come back to Narnia."
"Oh, Aslan!!" said Edmund and Lucy both together in despairing voices.
"You are too old, children," said Aslan, "and you must begin to come close to your own world now."
"It isn't Narnia, you know," sobbed Lucy. "It's you. We shan't meet you there. And how can we live, never meeting you?"
"But you shall meet me, dear one," said Aslan.
"Are — are you there too, Sir?" said Edmund.
"I am," said Aslan. "But there I have another name. You must learn to know me by that name. This was the very reason why you were brought to Narnia, that by knowing me here for a little, you may know me better there."
-- The Voyage of the Dawn Treader, Chapter 16: The Very End of the World
This says that Aslan does have an alternative identity in our world, but doesn't say explicitly who this is. Is it necessarily Jesus, or could it be another religious leader or legendary historical figure?
Is Aslan Jesus?
A more specific quote from the books would be great for an answer, though I'm pretty sure Jesus is never mentioned explicitly. Quotes from Lewis would also be fine, provided they're about an in-universe rather than allegorical identification of Aslan with Jesus.