I like how they made the Archdeacon not be evil, and saw right through Frolo's bullshit.
I also like how Frolo is a great example of the sort of Christian who Jesus would say "I never knew you" to.
The imagery was really nice as well. The opening sequence, with the statues of Jesus and all the Saints staring at Frolo, underlining the point the Archdeacon is making - You cannot hide your evil behind excuses and justifications to God.
Hellfire was nice as well, although my favorite sequence is when Frolo falls to his death - The Gargoyle he is clinging to transforms into a demon, and as he falls, he falls into a lake of fire - Pretty clear he is being dragged to hell for what he did.
Its okay for a children's movie. Has a good moral to it, even if it was accidental - You cannot hide your sins from God.