The song No Man Is An Island is about how everybody needs somebody how two is better than one. It was inspired by John Donne's poem "No Man is an Island" which is about the connection between all of humankind. Donne essentially argues that people need each other and are better together than they are in isolation, because every individual is one piece of the greater whole that is humanity itself. The paragraph isn't actually a poem but a famous excerpt from Donne's Devotions Upon Emergent Occasions.