You've set a wonderfully brooding, sombre tone with the language and imagery. It's a very stark piece, a good introspective monologue. I do think the ending could have been stronger. The captain doesn't come to a conclusion one way or another - either by retreating into his dogma or really starting to question it - and the story feels a little unfinished to me as a result. The contrast between dogma and reality is very strong in the story thanks to its powerful imagery, and I like what you're exploring here.