Kanji Lalji Mehta (Paresh Rawal), a middle-class atheist Hindu owns a shop of Hindu idols and antiques in Chor Bazaar, Mumbai. He is cursed by Siddheshwar Maharaj when he stopped his son from playing dahi handi. A low-intensity earthquake hits the city, and Kanji's shop is the only shop that is destroyed.

Next day at the insurance office, Kanji and his neighbour-assistant Mahadev learn that the disaster claim does not cover any damage caused by natural calamities classified under "Act of God". Running out of options, Kanji decides to file a lawsuit against God but fails to find a lawyer for such a lawsuit. Finally, he meets Hanif Qureshi (Om Puri) and his daughter (Puja Gupta), a poor Muslim lawyer family. Qureshi, a disabled man, helps him file the case as Kanji decides to fight on his own. Legal notices are sent to the insurance company as well as to religious priests, Siddheshwar Maharaj (Govind Namdeo), Gopi Maiyya (Poonam Jhawer) and their group's founder, Leeladhar Swamy (Mithun Chakraborthy) summoning them to the court as representatives of God on earth.

During the preliminary hearing, opposition lawyer Sardesai (Mahesh Manjrekar) asks the judge to dismiss the case. But Kanji points out that religious groups claim to represent God on Earth and speak on his behalf. Hence, they are answerable for his actions. The Judge agrees and the court accepts the case. However, Kanji soon finds himself trapped amongst armed fundamentalists, with his mortgage bank occupying the house, and his wife leaving him. In all instances, Kanji is rescued by Krishna Vasudev Yadav (Akshay Kumar), who claims to be a real estate agent, rides a hot-shot motorbike. Krishna buys Kanji's house from the bank, but allows Kanji to stay with him.

The lawsuit causes a public outcry. As Kanji and Krishna watch this on TV, Krishna advises him to go to the media and present his views to the public. Kanji's interview receives wide coverage and public opinion swings in his favor. Meanwhile, hundreds of people, whose insurance claims were rejected due to "Act Of God" show up at Hanif Qureshi's house and join the lawsuit. Kanji agrees to fight on behalf of all of them. In the next court session, Catholic priests and Muslim Mullahs are also summoned to the court as defendants. However, lawyer Sardesai points out that Kanji has no document that can prove the disaster was an "Act of God". The judge orders Kanji to present a written proof that will support his claim.

Kanji loses hope, but Krishna rescues the day again by advising Kanji to read the Bhagavad Gita, and the other holy books such as The Quran and The Bible, telling him that he would find the answer of all his questions. Kanji studies the books intensively for a month. In the next session, Kanji points out a passage in the holy books which says that "This world is a creation of God, and it is his will to allow it to grow or destroy", which strengthens his case. As he nears the end of his argument, he suddenly loses consciousness. He is rushed to the hospital, where doctors unsuccessfully try to revive him, leaving him comatose. They announce to the media that Kanji has been paralyzed, and that only God can now save him. When Kanji opens his eyes, he finds Krishna in front of him. Krishna caresses the left side of Kanji's body with his key chain and Kanji is able to walk again.

Krishna then reveals to the confused Kanji that he himself is Lord Krishna, and he has saved Kanji to show him that God does exist. Kanji then learns that he has been in a coma for a month and that’s a lot of things have happened during the period. The lawsuit's verdict was in his favor and religious organisations were ordered by the court to pay the compensation to all the plaintiffs; people have started calling Kanji a "God". Meanwhile, Leeladhar, Gopi Maiyya, and Siddheshwar have opened a temple dedicated to Kanji and accumulated millions in donations. He also learns that as per his own "will", he is about to be removed from the ventilator and thousands have gathered for his funeral procession. Krishna gives him a choice of stopping the procession or to sit back quietly. Kanji decides to fight and Krishna takes him on his motorbike to stop the procession. Kanji arrives to find his statues erected at the place where his shop once stood. He wades through the stunned crowd and breaks the statue, then admonishes the crowd about trusting in God-men. He advises them to search for God in themselves, not in statues. When the crowd's anger turns towards the collected God-men, he prevents them from further violence and tells them to allow the cheating group to leave peacefully, advising them not to believe in them anymore.

After successfully completing the job, he goes back to Krishna to thank him, only to find him and his motorcycle disappeared. Kanji's family arrive and they are reunited. On their way home, Kanji sees Krishna's key chain on the floor. When he is about to secure it inside his jacket, he hears Krishna's voice, telling him to get rid of the key chain as fear of god was what he fought against all this time. Kanji smiles and throws it away and sees it disappear into the sky with a flash