What is the main conflict in The Prophet by Khalil Gibran?

The Prophet presents the farewell observations on and recommendations about life and death of Almustafa, the chosen and beloved Prophet, as he ends a twelve-year sojourn in Orphalese.

Almustafa, the chosen and beloved Prophet around whom the story revolves, has spent twelve years of his youth in Orphalese, serving as the people's harp, flame, seeker of silence and guardian of the night. Much of his time has been spent in the overlooking hills, watching and listening to their lives. The people have generously met Almustafa's physical needs, but he realizes that some have criticized his aloofness. Now the ship he has been watching for to take him home arrives, and Almustafa comes down from the hills to the temple, bittersweet about leaving. The people gather to see him off, hungry to imbibe whatever wisdom he can deliver, for posterity's sake.