Lake Titicaca, impossibly wide and deep and high above the sea, fills an immense mountain trough in the Andes along the Peru-Bolivia border. The lake is so big that it encompasses rocky islands.

Strangely enough, there are floating islands too, giant rafts of totora reed supporting chickens, dogs, sheep and people. Houses sprout in organic rings around the islands. Men and women in rainbow woolen hats forever reweave their real estate as it ripples the aluminum-bright water.

I visited once. They’ve got a nice tourist gig going, and the floating island we stopped at sported a bamboo watchtower. I went up that watchtower and saw to the slow drift of the horizon.

We think of prophets hearing the word of God and relating it to the people. But prophets also see to the horizons of God’s intended future and watch for God’s kingdom.

Habakkuk, perhaps writing around the same time as Jeremiah, makes this prophetic watching clear as he describes the storm clouds of Babylon’s massing armies on the horizon.

His message is dotted with visual language. In chapter 1, it’s the “oracle that the prophet Habakkuk saw.” God invites Habakkuk to “Look at the nations and watch.”

In chapter 2, God tells him to “write down the revelation/ ­vision.” Habakkuk steps out of the fray and climbs up his watchtower to get perspective on God’s farther and broader horizon.

Part of what makes Habakkuk such a compelling book is that the prophet not only watches and listens. He ascends the watchtower to speak to God.

One way to read the book’s structure is as a series of questions put to God by the prophet (1:2-4; 1:12-17), followed by God’s responses (1:5-11; 2:2-20).

Habakkuk resolves in an intense prayer-psalm called a ­Shigionoth of complete abandonment to God (3:1; see Psalm 7). Though the world fall apart, “yet I will rejoice in the Lord” (3:18).

Habakkuk is not alone in the Scriptures in putting questions to God. Just read Job or Ecclesiastes. Dive into the words of the prophet Jeremiah. Just ask David how he felt when Uzzah was struck dead steadying the sacred ark of the covenant on that oxen-rocked cart (2 Samuel 6).

Habakkuk questions how God can use such a violent and immoral and destructive people (Babylon) to punish his beloved children (Israel). He asks how God can treat human beings as if they were nothing more than creeping things from the depths of the sea, fish to be trawled up in a net (1:12-17).

Habakkuk is speaking of Babylon and Judea, but his are age-old, universally human questions of God’s justice, God’s power, God’s goodness.

The prophet’s watchtower is for watching in holy silence (2:20). But the watchtower is also for placing deep and soul-troubling questions before the Rock, the Holy One of old (1:12).

So too the prophet Amos, who “saw” his own set of words in the days of kings Uzziah and Jeroboam. He looks to the horizon and sees God’s coming judgment, sees even to the “day of the Lord.”

But it’s no I-told-you-so vision. No one can rest comfortably, not the Scripture-learned nor the religious.

“I despise your festivals,” says the God of Amos (5:21). “I can’t stand your religious meetings. I’m fed up with your conferences and conventions” (5:21-22, The Message). I don’t want your burnt offerings or grain offerings or fat offerings or blood offerings (5:22-23).

Thus saith the Lord: Give me justice rolling down like water and “righteousness like an ever-flowing stream” (5:24).

Anybody can affect a religious demeanor. Anybody can lob questions at the sky. Both can become ways of keeping God safely at arm’s length. But it’s another matter entirely to put yourself in a position of openness and vulnerability before the Ancient of Days. How do you go up the watchtower?

Brad Roth is pastor of West Zion Mennonite Church in Mound­ridge, Kan., and author of God’s Country: Faith, Hope and the ­Future of the Rural Church ­(Herald Press). He blogs at ­DoxologyProject.com.