It's not a Bible verse you hear in many churches. At the end of Psalm 137, a lament by the Jewish people exiled in Babylon, come these words:

"O daughter Babylon, you devastator! Happy shall they be who pay you back for what you have done to us! Happy shall they be who take your little ones and dash them against the rock!"

Those are just two of the scores of verses in the Bible that speak of wrath and vengeance and portray violence and destruction.

In the face of this disturbing imagery, Jerome Creach has set himself a daunting task: to explain why these verses are in Scripture, and how Christians should interpret them.

Dr. Creach, the Robert C. Holland professor of Old Testament at Pittsburgh Theological Seminary, is working on a book on violence in the Bible and presented a four-part public lecture series on the topic in January.

"I'm writing the book mainly for pastors, people who have a theological education but whose education has not equipped them to deal with these kinds of issues," he said.

And even though he's willing to take on the task, he's the first to admit it's not easy. At a time when people see Muslim terrorists using their faith as a justification for violence, and atheist authors blaming Christianity for much of the bloodshed in world history, the angry, destructive passages of Scripture are troublesome for many people of faith.

First and foremost, Dr. Creach said, he does not believe the Bible condones human violence or holds it up as a fundamental standard of behavior.

But he is also not willing to simply ignore the passages that contain violence without trying to understand their meaning for the people who wrote them and for those who read them today.

One passage that troubles many Christians and Jews is the beginning of Chapter 7 in Deuteronomy, when the Israelites who escaped Egypt have finished their wandering in the desert and are about to occupy the land of Canaan.

"When the Lord your God brings you into the land that you are about to enter and occupy, and he clears away many nations before you ... then you must utterly destroy them. Make no covenant with them and show them no mercy."

The Hebrew term for "utterly destroy" is a word used to denote ritual annihilation, Dr. Creach said, a concept that also was used by other ancient Near Eastern tribes in describing how to treat a conquered enemy.

And while that seems plain enough, early interpreters and the Bible itself raise a lot of questions about how literal the meaning of the passage is.

A primary concern of the biblical authors, Dr. Creach said, was that the Canaanite tribes worshipped other gods and might tempt the Jews into shifting their devotion away from their God, Yahweh.

That shaped the view of one early church father on how to interpret the passage, he said. In the third century after Jesus, the Alexandrian theologian Origen said that "the real and most important meaning [of the verses] is for the spiritual life of the believer ... urging us to root out all the spiritual vices that threaten us in our lives."

And the Bible itself makes it clear the slaughter is not to be taken literally, Dr. Creach said, because in the very next verse, the Jews are warned not to intermarry with the other tribes. As he put it drily during his lectures, there is seldom a temptation to marry those whom you've already killed.

"So my point is that when you read these passages really carefully and read them in the context of the Bible as a whole, they really are metaphorical."

Dr. Creach came to this subject after he had been asked to write a commentary on the book of Joshua, which contains many of the Canaan conquest stories.

Raised as Southern Baptists, he and his wife, the Rev. Page Creach, switched to the Presbyterian Church after Dr. Creach obtained his doctorate in Old Testament studies at Union Theological Seminary in Virginia.

The Psalms -- his special area of expertise -- also are filled with pleas to destroy Israel's enemies and punish the wicked.

But even a verse as harsh as the one about dashing Babylonian children against the rocks must be seen in context, he said.

Psalm 137 was written after a real historical event, in which the kingdom of Judah was conquered by the Babylonians in 587 B.C. and many of its leaders were taken into exile in Babylon, which was centered in modern-day Iraq.

When the psalm calls for the Babylonian children to be killed, "we can't take away the shock of it," Dr. Creach said. But it probably is aimed at the children of Babylon's rulers. "The real meaning of this, as scholar Erich Zenger says, is 'Happy is the one who seizes you and puts an end to your rule.' "

There are so many psalms that call on God to punish the people's enemies that they even have their own name -- imprecatory psalms.

But it's important to remember that many of these psalms were written after the Babylonian exile, he said, and come from the perspective of a defeated and enslaved people.

"These are people who have lost their land," he said. "They're not people who can conquer anyone. So from that perspective, these stories really do take on a different meaning."

Even though we may not like the image of an angry God, "if we read the Bible from the perspective of the poor and the oppressed, don't we want and expect a God who is concerned about justice and who ultimately will bring about justice for those who are on the underside of the world?"

By the same token, he said, it disturbs him when people in powerful positions use these passages to justify their disputes with others.

One particularly egregious example of that, he said, was a California pastor who last year asked his parishioners to use Psalm 109 in prayers against a group that had called on the Internal Revenue Service to investigate his church's tax-exempt status.

The Rev. Wiley Drake told church members to use the psalm in prayers against two officials of Americans United for Separation of Church and State, who had objected to the Rev. Drake's open endorsement of Republican presidential candidate Mike Huckabee.

Among the verses he wanted them to use was one that said: "May his children be orphans, and his wife a widow."

The psalms often call on God to avenge the righteous, who are often identified as the poor and needy, Dr. Creach said. But they are not meant for "people who pray petty prayers against their enemies -- there are bigger issues at stake. That's why this pastor in California was misusing those imprecatory psalms."

Many Christians try to deal with the violence in the Old Testament by saying that the God portrayed in the New Testament is a kinder, gentler deity than angry Yahweh.

But even though Jesus told his followers to love their enemies, turn the other cheek and accept the little children, he also chased the money changers out of the temple, called the Pharisees a brood of vipers and spoke of eternal damnation and torture.

For that reason, it doesn't work to just mentally block out the Old Testament depictions of God, Dr. Creach said. And because the Bible doesn't come with an instruction manual, it requires study and reflection to try to put all these conflicting messages into perspective, he said.

One way he does that is to zero in on the very beginning of the Bible, the creation story in Genesis 1.

Unlike other ancient Near Eastern creation stories, in which gods battle each other to create the world, he said, "In Genesis 1, you have God creating the universe without any conflict. The first violence is done by human beings, in the later story of Cain and Abel. And then there's this downward spiral of violence and it reaches its height at the time of the flood story," in which God wipes out creation, but saves Noah's family and the animals needed to regenerate the earth.

Even after the flood waters recede, however, human beings continue to be violent and disobey God, he said, and despite that, God promises not to destroy them again.

"So in effect," he said, "God becomes more gracious because human beings weren't going to become more obedient. In the end, I think that's the picture of God that I take as normative in the Bible."