The Pulpit Is Its Prow

Let's get this metaphor straight. Here's a look at Father Mapple's pulpit in Chapter 8:

Its panelled front was in the likeness of a ship's bluff bows, and the Holy Bible rested on a projecting piece of scroll work, fashioned after a ship's fiddle-headed beak.

What could be more full of meaning?—for the pulpit is ever this earth's foremost part; all the rest comes in its rear; the pulpit leads the world. From thence it is the storm of God's quick wrath is first descried, and the bow must bear the earliest brunt. From thence it is the God of breezes fair or foul is first invoked for favourable winds. Yes, the world's a ship on its passage out, and not a voyage complete; and the pulpit is its prow. 

So, God's action's are the Weather and we are all Crew on the Ship sailing into God's Seas. The pulpit is the Bow, from which we're getting the latest Weather Report on God's "quick wrath." For now, the man standing on the bow is Father Mapple, giving a sermon that is great but, essentially, a warm-up act. Because soon it'll be our Everyman, Ishmael, standing on the pulpit of the Pequod. From that bow, there will be some serious descrying as we get the Weather Report for humanity. In some ways, this is what Moby-Dick is, a sermon for the ages, one we continue to discuss today, trying again and again to discover God's mysterious disposition.