A long, dry period for public theology in the United States followed the death of Reinhold Niebuhr – a period that has seen the rise of forms of fundamentalism in every religion there is. Fortunately Garry Wills has been offering tall glasses of water for thirsty readers interested in religion, whether believers or skeptics.

Mr. Wills has brought religion back into the public arena with books that combine historical acumen and insight into the practice of faith. Whether he has turned his attention to St. Augustine’s thought or to the role of the papacy in the modern church, he is more than a Catholic or Christian intellectual. He has signaled the return in the United States to a desire to understand faith, not just to defend some strident ideology or another – Catholic, Protestant, Muslim, Jewish, New Age, and/or secularist.

Mr. Wills’s decision to turn his attention to the question of Jesus in his latest book, “What Jesus Meant” (Viking, 144 pages, $24.95), is full of promise. At no time since the fourth century has there been as much debate as there is now about Jesus. While ancient controversy pivoted on whether Jesus was divine, today’s disagreements are historical – concerning what Jesus did and said. With a shrewd awareness that the current historical debate is only heated because our underlying interests remain theological, Mr. Wills here writes what he calls a devotional book. During the season of Lent, Christians through the ages have focused on the image of Jesus while preparing themselves for baptism, taking on disciplines of penance to identity their sins and seek forgiveness, and deepening their faith. Lent is the special time for “faith seeking understanding,” the slogan Mr. Wills takes from St. Anselm as his guiding principle.

Mr. Wills writes devotionally, but with historical awareness. (Still, there are mistakes in the book: For example, the New Testament as a whole is not written in a “pidgin” language, Jesus did have priestly followers, his disciples did not come from “the working class,” and Joseph did not manufacture cabinets.) He is impatient with glib assumptions that the Gospels endorse modern American values and peppers his book with scathing references to televangelists who have turned Jesus’s message into a money machine. But Mr. Wills also complains that professional academics have their own fundamentalisms that play down the religious significance of Jesus. He targets the “Jesus Seminar” in particular, calling them the “Seminarists” so effectively that the reader can practically hear a sibilant “s” hissing from the page. There is a degree of exaggeration here, of course, but Mr. Wills is right to complain: Some academics do explain religion away by reducing it to wishful thinking or to coded forms of politics.

The modern master of devotional writing with controversial asides and scintillating insights was G.K. Chesterton, whom Mr. Wills often quotes and deliberately emulates. Mr. Wills follows up his initial comments about the various fundamentalisms of our age, secular and religious, with acerbic remarks with regard to Pope Benedict XVI. These comments emerge as Wills offers generous support for various causes and movements: He is for the acceptance of homosexuals by Christians, for renewed engagement on behalf of the poor, and for recognition of the Anglican Church as a branch of the apostolic faith shared with the Vatican.

Deep contentions cannot be settled with a few paragraphs, even from the most fluent of pens. Relations between the Anglican and Roman Catholic Churches have been fraught since the 16th century, and their divisions go beyond the dispute over whether one side or the other can rightly claim apostolic authority. Even if, as Mr. Wills says in a striking phrase, Jesus “walks through social barriers and taboos as if they were cobwebs,” homosexuality is a bigger cobweb than most. Jesus said nothing about the Levitical law in this regard, and Paul was explicit in his condemnation of homosexual practices. To see attitudes toward homosexuality as rooted in questions of purity is incisive, but the simple fact is that Christianity has not dispensed with standards of what is pure and impure. And finally, it is difficult to argue that the oppression of the poor is really more the fault of the Roman Catholic Church than the Enrons of this world.

Mr. Wills’s remarks at Pope Benedict’s expense might grate on some readers as the book progresses. The pope comes off as grudging toward Anglicans, phobic over homosexuals, and heartless with regard to the poor. Even if you agree with Mr. Wills’s opinions in general (as I do), you might be troubled that Pope Benedict takes more abuse than the secular “Seminarists.” This is natural enough to some extent; Christians are typically tougher on their own folds than on other flocks.

But there is a deeper reason for this antagonism toward Pope Benedict that reveals a flaw in Mr. Wills’s otherwise exemplary meditation for Lent.

When he criticizes Pope Benedict, Mr. Wills falls into a standard Protestant objection, articulated from Luther onward: that there is just too much wealth in the Vatican that is expended in the interests of ceremony. Protestants used to riff about this much more than they do now, turning their objections into personal attacks on whoever the current pope was. For Mr. Wills to take up the cudgels is a bracing example of the ecumenical spirit of our age, but strangely anachronistic.

Mr. Wills excoriates Pope Benedict’s devotion to sacrificial worship, which is a betrayal of Jesus as far as Mr. Wills is concerned. His Jesus is against all sacrifice, the whole structure of the worship of Israel, and anything that looks like that. You wouldn’t predict, from this book, that Jesus told people how to offer their gifts at the Temple and insisted on the requirement of sacrifice, or that Paul’s final arrest occurred when he was taking part in sacrifice in the Temple. The New Testament insists upon those simple facts, in addition to agreeing with the prophets of the Hebrew Bible that life revolves around celebrating the presence of God with the joy and festivity of sacrifice.

This lapse is all the stranger, because on other fronts Mr. Wills does reflect an awareness of recent advances in the study of Jesus. He agrees with me, for example, that the Gospels often portray a long process of development as a single event (Jesus’s baptism being a case in point), that Jesus was accused by some of his contemporaries as being born illegitimately (although “bastard” puts the charge too strongly), and that in Jesus’s resurrection “the body was not the earthly body anymore.” So why, having learned so much from recent scholarship, does Mr. Wills balk at admitting that, as an Israelite of the first century, Jesus approved of sacrifice?

This is just where a devotional writer should be probing his own motivations, rather than jousting with popes and televangelists. What if Jesus meant what he said? “If anyone wants to follow after me, deny oneself and take one’s cross and follow me!” Then, Lent would be a time when those who see the wisdom of Jesus’s way would not just venerate him, but enter intentionally into discipleship, a sacrificial path. Of course, that would mean that the current American conviction, that all we want can be possessed without cost, is dubious. Perhaps that is a good possibility to entertain this Lent.

Mr. Chilton is the author of “Rabbi Jesus: An Intimate Biography,” available from Doubleday.