Much is wrapped up in Samuel Taylor Coleridge's poem The Rime of the Ancient Mariner. The obvious is that there are consequences to every action. When the sailor killed the albatross, suffering and death were inflicted on the entire crew. The mariner was the only one from the crew who lived, and his punishment was to tell his story over and over. He was sentenced to a life where he is trapped between life and death.
Coleridge also had a fascination with the natural world and the power that it contains. Man, no matter how hard he tries, cannot control the power of the ocean or the weather. The mariner learns how very important it is to respect nature and the spiritual world as well.
That spiritual world also exists in this poem. The dead sailors come back to life for a time, inhabited by some sort of spirit, and the albatross is also connected to the other side.
Coleridge conveys much more in his poem--themes of being imprisoned, religion, and punishment. He tells a story through poetry that is beautiful, but also makes his readers think.