Antonious Nicholas, thank you for your post. Have you read The Idiot
by Dostoevsky? There is also a great mini-series (titles IDIOT) Work on this character (prince Myshkin, the idiot) transformed the actor in real life.
I watched this movie ISLAND twice. Obviously it is not intended for popcorn oriented audience or people looking for pure entertainment. I got that before I became a Christian and this film was... well, different, nostalgic and visually appealing. Now I watched it as an Orthodox Christian and it was a new movie entirely!
It hits you with an incredible combination of stillness and intensity. This is how life in a monastery might feel to its inhabitants: so peaceful and still outside, and so loaded with personal spiritual battle. The "podvig" he took upon himself (being a Fool for Christ, asceticism) speaks of his true love for God (with all the heart, and might and soul).
It also explained to me the second commandment: love thy neighbor. The ugliest-looking man committed the most atrocious act (betraying, and then shooting his captain out of cowardliness) but... he repented! And suddenly you have hard time letting him go. Father Anatoly, don't go yet, stay and pray for us, sinners.
The first-time actor Mamonov is superb. It must be hard to genuinely pray, and yet, one believes his every word and move. By the end of the movie, we see him taller and stronger, with wider chest... now we see his enlightened spirit and trust him. No question that he can cast demons, heal people and see into hearts of brother monks.
Symbolism? First thought: Coals and fire as a metaphor of sins burning our souls... Second thought: perhaps our life here is hell, we are living it... and the coffin? is not the end, it is the EXIT. It is also a symbol for material things in life and how funny it is to worry about the quality of one's coffin
Still people kill for "finer things in life", they think they need а polished coffin.
This movie is a soul-detector. If it does not move you, it is quite alarming.