This is not a poem, but Walt Whitman used poetic language and deep meditative thought it qualifies. He used  language in ways that are politically incorrect today, but provided considerable insight into what it might mean to be a servant-leader and live in the world that way.

I become part of the world and it is embodied in me in such remarkable ways as I learn from the world. I think that is the counsel that this passage provides for me and asks of me.

“This is what you shall do: love the earth and the sun and the animals, despise riches, give alms to everyone that asks, stand up for the stupid and crazy, devote your income and labor to others, hate tyrants, argue not concerning god, have patience and indulgence toward the people, take off your hat to nothing known or unknown or to any man or number…