During Chapter 14 and 15, readers of the book witness a remarkable sacrifice, and an even more remarkable resurrection. Many critics have described this sacrifice as an allusion or allegory. Whether you believe in Christianity or not, the similarities are interesting for us to study.
First, Aslan willingly sacrifices his life to save the lives of those he loves. In the Bible, Jesus willingly forfeits his life to save the souls of all his followers.
Second, Aslan easily could have destroyed all of the villains who tormented him at the Stone Table. Jesus chose to die without struggle, even though he could have asked his Father (God) to destroy all of the men who were about to kill him.
Third, Aslan was tortured by the evil creatures of the White Witch. He had his hair cut, he was stabbed and muzzled. During his crucifixion, Jesus was stabbed in the side, and he had a crown of thorns jabbed down onto his head.
Fourth, Aslan was killed on the Stone Table. Jesus crucifixion occurred at Calvary, a hill of rocks rumoured to be the place where Adam's skull was buried.
Fifth, Aslan returned to life after the Deeper Magic was revealed. Jesus returned to life three days after his death, and was brought to Heaven by God.
Of course, this is only one of the symbols in the book. Although C.S.Lewis was deeply religious, the book also makes several historical allusions. In this case, the Lion might be symbolic of the British Empire itself. After all, Britain was nearly destroyed by the Nazi bombs during the Battle of Britain. However, it rose up to eventually defeat Hitler's forces. The most dominant symbol of Britain is the Lion.
check out the statues (both famous London sculptures), and the British Banner (which includes the symbols of the four nations making up the United Kingdom)
