IN December, the Bollywood film "PK," an ingenious comedy-drama about a confused extraterrestrial and the Indian subcontinent’s obsession with religion, opened on thousands of screens all over the world (including 272 screens in the U.S.).

A month later, it has become the most profitable Bollywood film of all time, as well as the biggest-ever Bollywood hit in America. Starring the ever-reliable and cinematically ambitious superstar Aamir Khan, the success of "PK" is actually well deserved (many Hindi superhits are truly juvenile).

Sure, it hews close to the traditions of Bollywood cinema - - it is rich in spectacle, song and dance, and it takes a view of human emotion that may in the West come across as full of sentimentality, often cited as a reason for the genre’s lack of crossover appeal. But "PK" also demonstrates how a mass art form can fold a skeptical and challenging message into a pleasing plotline, and it is an extremely timely intervention in the ugly wars over religion in India today.

In the film’s opening scene, a spaceship lands in the middle of the Rajasthan desert (“Why do all aliens land only in India?” asked a man sitting in the row behind me), and there emerges the film’s good-looking but expressionless hero. He is stark naked, except for a glittering green pendant around his neck: the device with which he can send messages back to his home planet.

Immediately, a man steals this device from him, and language-less PK -- on his own planet, all communication is telepathic -- is left without any means of connection to another being, whether on this planet or his own. He blunders around the countryside, desperate to find his transmitter, and arrives after many travails in New Delhi.

By this time, he has picked up a rustic, trenchant north Indian dialect, Bhojpuri, as a result of an encounter with a prostitute in which no bodily fluids are exchanged, only language (this is one of the film’s many daring touches). Now he finally has the means to ask questions of human beings and track down his transmitter, but almost everyone he meets in Delhi gives him some version of the answer “God only knows” or “Only God can help you.” PK decides to track down God in India, and spends all his time following and imitating all those who are also apparently in search of God in temples, mosques and churches.

Without knowing it, then, he becomes the latest incarnation of one of the subcontinent’s great religious lineages: the questioning figure (Lal Ded, Kabir, Gandhi) who, through his or her skepticism, mockery, moral nobility or innocence, puts to shame those passionate believers -- whether within a religious tradition or across all of them -- who think they know what faith is all about. Looking at the world though PK’s perplexed eyes, the Indian viewer sees a new line drawn through one of the most diverse and layered religious landscapes in the world: one that suggests that all religions have been captured by complacency, arrogance, empty rituals and blind faith.

And yet the satire is delivered with an empathetic and peculiarly Indian touch, with a sense that religious belief is not so much an irrational human excess to be discarded, but a challenging road on which it is quite easy to go -- or be led -- astray, and the same bad faith that attaches itself to so many human projects is once again conspicuous.

The film's harrowing song “Bhagavan, Hai Kahan Re Tu?” (“God, Where Art Thou?”) describes PK’s anguished search for a god beyond that of images and words who will answer his questions. It expresses the film’s message in a much more tragic and troubled key than the plot itself, a kind of layering intrinsic to Bollywood’s film language that the reviewer in the New York Times seemed to have missed while deciding that the film was essentially a well-meaning bit of cinematic candyfloss. To me, there was something extremely moving and convincing about PK’s journey to his eventual, unsettling conclusion: “There is not one God, but two: the one that made human beings, and the one that human beings made.”

Predictably, soon after its release, "PK" became the object of vociferous protests in India by right-wing Hindu groups that thought Hinduism was unfairly singled out in the film’s critique of religion and wanted the film banned by the state or at least boycotted by Hindus.

But the film’s focus on Hinduism is not because it somehow holds Hinduism to be more susceptible to corruption and bad faith than the other religions of India. It is rather that, precisely because a majority of Indians are Hindu, political Hinduism can destroy the delicate ecosystem of religion on the subcontinent in a way that no other force can, and with the very complacency and self-righteousness exhibited by the Hindu godman who is the film’s villain.

A blockbuster made in a warmly mocking spirit and starring the most charming alien ever seen in Indian cinema, "PK" is a reminder of how the best art can endow us with a new vision of the familiar and a new imagination for the future.