Stephen Prothero, a Boston University religion scholar and author of "God is Not One: The Eight Rival Religions that Run the World," is a regular CNN Belief Blog contributor.

By Stephen Prothero, Special to CNN

I am a big fan of the Dalai Lama. I love his trademark smile and I hate the fact that I missed his talks this week in New York City. But I cannot say either "Amen" or "Om" to the shopworn clichés that he trots out in the New York Times in “Many Faiths, One Truth.”

Recalling the Apostle Paul—“When I was a child, I spoke like a child”—the Dalai Lama begins by copping to youthful naivete. “When I was a boy in Tibet, I felt that my own Buddhist religion must be the best,” he writes, “and that other faiths were somehow inferior.” However, just as Paul, upon becoming a man, “put away childish things,” the Dalai Lama now sees his youthful exclusivism as both naïve and dangerous. There is “one truth” behind the “many faiths,” and that core truth, he argues, is compassion.

Like the Dalai Lama, who writes of how he was influenced by Thomas Merton, I believe we can learn greatly from other religions. I too hope for tolerance and harmony in our interreligious interactions. I am convinced, however, that true tolerance and lasting harmony must be built on reality, not fantasy. Religious exclusivism is dangerous and naïve. But so too is pretend pluralism. The cause of religious harmony is not advanced in the least by the shibboleth that all religions are different paths up the same mountain.

If you ask religious universalists what lies at the top of the mountain, the answers they will give you are not one but many. Gandhi and philosopher of religion Huston Smith say that at the top there is the same universal God. But when others describe this religious mountaintop they invariably give voice to their own particular beliefs and biases.

Followers of the Dalai Lama revere him as a reincarnation of Avalokiteshvara, the bodhisattva of compassion. So it should not be surprising that he sees compassion at the heart of all religions. But this is a parochial perspective, not a universal one. And like any form of pretend pluralism it threatens to blind us both to the particular dangers of individual religious traditions and to their unique beauties.

To be sure, all religions preach compassion. But it is false to claim that compassion is the reason for being of the great religions. Jesus did not die on a cross in order to teach us to help old ladies across the street. The Jewish milieu in which he was raised already knew that. And as the Dalai Lama points out, so did the rest of the world’s religions. Jesus came, according to most Christian thinkers, to stamp out sin and pave the path to salvation. Similarly, the Buddha did not sit down under a Bo tree in India in order to teach us not to kill our brothers. The Hindu milieu in which he was raised already knew that too. He came, according to most Buddhist thinkers, to stamp out suffering and pave the path to nirvana.

As I argue in my new book, "God is Not One: The Eight Rival Religions That Run the World—and Why Their Differences Matter," religion is an immensely powerful force both personally and politically. So if we want to understand the world we must understand the world's religions. This includes reckoning with both similarities and differences, and with the capacity of each of the great religions to do both good and evil.

I know that when it comes to the Dalai Lama we are all supposed to bow and scrape. So I am happy to applaud his project to find “common ground” across the world’s religions. But I also know that the Buddha said to worship no man. And I cannot agree with the Dalai Lama’s claim that “the essential message of all religions is very much the same.”

The Dalai Lama was doubtless naïve when, as a boy, and before learning about other religions, he arrived at the conclusion that only his religion was true. But it is no advance out of innocence to make the equally fantastic claim that all the religions are at heart vehicles for compassion. If we are to build a world of interreligious harmony, or even a world of interreligious détente, it will have to be constructed on a foundation of adult experience rather than youthful naivete.

The opinions expressed in this commentary are solely those of Stephen Prothero.