What metaphors are used in Bonhoeffer: Pastor, Martyr, Prophet, Spy by Eric Metaxas?

The author, Eric Metaxas, is a professed Christian. Having received a revelation of the presence and power of the living Christ in a dream in his mid-twenties, he writes from a perspective that is, in many ways, similar to that of his subject. Some people consider Eric to be a symbol or metaphor of a prophet.