Narnia is supposed to be a fantasy version of the events of the life of Jesus. The lion is Jesus, who died to save all mankind (in the books, all the anthropomorphs/)
Edmond represents Judas. The reason Judas betrayed Jesus is because Jesus had to be betrayed in order for events to play out and Jesus killed.
In the end, when the children sit on thrones alongside Asland, this represents how those who are beheaded for their testimony of Jesus will be part of the 1st resurrection, and live and reign with Jesus ON THE EARTH for 1000 years. Then, Satan (the white witch) is released for a short time, but sent into the Lake of Fire, where the antichrist and false prophet are already.