Kanji Lalji Mehta (Paresh Rawal), a middle-class Hindu atheist owns a shop of Hindu idols and antiques in Chor Bazaar, Mumbai. One day, a low-frequency earthquake hits the city, and Kanji's shop get completely destroyed.
Next day at the insurance office, Kanji and Mahadev (his neighbour) lea 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 goes to Hanif Qureshi (Om Puri), a poor Muslim lawyer. Qureshi, a disabled man, helps filing the case as Kanji decides to fight on his own. Legal notices are sent to the insurance company, as well as all religion 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, opposite lawyer Sardesai (Mahesh Manjrekar) asks jury to dismiss the case. But Kanji points out that religious groups claim to represent God on Earth and speak on behalf of him. Hence, they are answerable for his actions. The Jury agrees and the court accepts the case. However, Kanji soon ends up in front of a group of fundamentalists who try to kill him but he is saved by Krishna Vasudev Yadav (Akshay Kumar).
The lawsuit causes a public outcry. As Kanji and Yadav watch this on TV, Yadav tells him to go to the media and put his view in public. Kanji's interview receives wide coverage and public opinion swings in his favour. Meanwhile, hundreds of people, whose insurance claims were rejected due to "Act Of God" show up at Hanif Qureshi's house and join lawsuit. Kanji agrees to fight on behalf of them. In the next court session, Catholic priests and Muslim Mullahs are also summoned to the court as defendants. However, lawyer Sardesai points that Kanji has no document that can prove the disaster was "Act of God". The judge orders Kanji to present a written proof that will stand by his claim.
Yadav tells Kanji to read the Bhagavad Gita, and all holy books, such as Quran and The Bible to find 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". Suddenly, he gets unconscious. He is rushed to the hospital, where doctors unsuccessfully try to revive him, leaving him in comatose. Yadav shows up & revives Kanji from his paralized state. Yadav reveals Kanji that he is Lord Krishna.
Kanji, then leas he has been in coma for a month and things happened during the period. The lawsuit's verdict was in his favour and religious organizations were ordered by court to pay the compensation to all the plaintiffs; people have started calling Kanji a "God". Meanwhile, Leeladhar, Gopi Maiyya, and Siddheshwar have opened Kanji's temple and accumulated millions in donations. And today, as per Kanji's will, he is about to be removed from the ventilator, and thousands have gathered for his funeral procession. Kanji rushes to the place with Krishna to stop the procession. He addresses the crowd, destroys his own statue and tells them to tear down the temple.
He then comes to Yadav to thank him, but is distracted for a second by the crowd pulling down his statue. Meanwhile, Yadav and the motorcycle disappear. As he reunites with family, finds Yadav's key chain on the ground. When he is about to secure it inside his jacket, hears Lord Krishna's voice, telling him to get rid of the key chain as idol worship was what he fought against all this time. Kanji smiles and throws it away in the sky.