It's still someone's opinion, but they are using scripture to back them up and using their interpretation of said scripture. When you get right down to it, it is still an opinion.
C.S. Lewis may indeed have been a Christian towards the end of his life or on his deathbed (Only God knows), but he also claimed that he struggled with the occult and it shows in his writings. He also believed in Evolution. He believed Adam and Eve were not literal people. He believes much of the Old Testament is mythical. He denies the Substitutionary Atonement. He believes people of other religions (who continue in that religion and don't change) can be saved. He believes that a belief in a literal Satan is not necessary as a part of the Christian faith. He believes that the Bible has errors in it. He believes that other books besides the Bible can be inspired (Note: See the link within this thread for the sources of C.S. Lewis's quotes to support these claims).
In fact, here is a quote by C.S. Lewis on Jesus' prophecy of the End Times:
"Say what you like," we shall be told, "the apocalyptic beliefs of the first Christians have been proved to be false. It is clear from the New Testament that they all expected the Second Coming in their own lifetime. And, worse still, they had a reason, and one which you will find very embarassing. Their Master had told them so. He shared, and indeed created, their delusion. He said in so many words, 'this generation shall not pass till all these things be done.' And he was wrong. He clearly knew no more about the end of the world than anyone else. It is certainly the most embarassing verse in the Bible. Yet how teasing, also, that within fourteen words of it should come the statement"
The man appears to reject Scripture, which does not seem Christian like to me, even if he may been converted to Christianity towards the end of his life or on his deathbed. But the problem is people are eating up his occult fantasy books like candy.
Narnia portrays characters that are from real life paganism (i.e. the occult). The faun that Lucy runs into is Pan (who is a god of lust). What is a god of lust doing when he hangs out with a little girl by himself? There are other pagan gods mentioned, as well.
p. 192 - "
Bacchus and the Maenads ---
his fierce, madcap girls --- and
Silenus, were still with them. Lucy, fully rested, jumped up. Everyone was awake, everyone was laughing,
flutes were playing, cymbals clashing.
Animals, not Talking Animals, were crowding in upon them from every direction.
" 'What is it, Aslan?' said Lucy, her eyes dancing and her feet wanting to dance.
" 'Come, children," said he. 'Ride on my back again to-day.' "
" 'Oh lovely!' cried Lucy, and both girls climbed on to the warm golden back as they had done no-one knew how many years before. Then the whole party moved off ---
Aslan leading.
Bacchus and his Maenads leaping, rushing and turning somersaults,
the beasts frisking round them, and
Silenus and his donkey bringing up the rear." [Emphasis added.]
Now, note here that Lewis actually names the Maenads and describes them as "fierce". To complete the description of this devil worship for your children to mimic in their play, he adds the flutes and cymbals, and animals are brought in, though their fate at the hands of the Maenads is carefully excluded.
He also describes them going down a hill into town where they found a girls' school. The girls were dressed in ugly tight collars, thick stockings and tight hairdos. The teacher and class all fled in terror except one girl. Aslan called her "sweetheart" and asked her to join his wild crowd, which she did. She was instantly dancing with the Maenads who helped her take off some of her "unnecessary" and uncomfortable clothes!
So, Lewis is telling your children that in order to be part of this wild bunch (which he portrays as fun), they must join in the dancing and take off some of their clothes!
This sounds remarkably similar to one of the accounts in the Bible -- the occasion on which Aaron made the golden calf and Israel worshipped it with a wild feast and dancing party. When Moses got back down the mountain, he confronted Aaron and received a stupid excuse. Then we read,
Exodus 32:25 And when Moses saw that the people
were naked; (for Aaron had made them naked unto
their shame among their enemies ; 26 Then Moses stood in the gate of the camp, and said, Who is on the LORD'S side?
let him come unto me. And all the sons of Levi gathered themselves together unto him. 27 And he said unto them, Thus saith the LORD God of Israel, Put every man his sword by his side,
and go in and out from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour. 28 And the children of Levi did according to the word of Moses: and there fell of the people that day about three thousand men.
From this account we can see that the LORD does not look lightly on this sort of thing. Allowing C.S. Lewis to teach your children such heathenism is perilous to say the least!
Source used for the latter half of this post.
C.S. Lewis depths of Satan, Chronicles of Narnia, Dionysus
Other source used to reference C.S. Lewis' false beliefs:
CS LEWIS – The most beloved heretic