Kejriwal said the party's electoral win in Varanasi and Amethi would be "enough to shake up the country" even if the rookie party does not win 100 seats in the Lok Sabha poll.
"Modiji brought me to Varanasi. And this is not a battle of prestige, but one to save the country from corrupt forces like the BJP and the Congress," Kejriwal told IANS after his hectic and back-breaking campaigning in the temple town.
In Amethi, the Aam Aadmi Party (AAP) has fielded Kumar Vishwas against Congress vice president Rahul Gandhi.
Asked whether it was purely out of electoral reasons that he decided to contest in Varanasi, Delhi's former chief minister Kejriwal said: "It is not so... Wherever the Aam Aadmi Party enters once, it maintains an everlasting tie with that place and its people."
"We have come to Varanasi and we will never leave it," he adds.
Varanasi will go to the polls May 12. The contest between the Gujarat chief minister and Kejriwal is the most keenly-watched contest, in which the former seems to have the upper hand.
Both the leaders filed their nomination papers accompanied by large numbers of supporters and their cavalcades.
Modi's road show - a day after Kejriwal's - was joined by thousands, sending out a strong signal of his popularity.
Besides Modi, Congress' Ajay Rai is another contender.
Asked about the number of seats AAP was hoping to muster in the house of 543, Kejriwal said: "We will get what people will give. I am not worried about the results.
"Imagine you seeing news on TV and coming to know that both Modiji and Rahul Gandhiji got defeated.
"The Congress will be destroyed and BJP will cease to exist," he added.
As to why the over a-year-old party did not wait for the 2019 general election, Kejriwal answered: "People said we should have contested 30 seats (in Lok Sabha) and gradually taken the graph higher, but that is conventional politics.
"Had we waited till 2019, the country would not have been there," he said.
Perhaps, the biggest challenge for Kejriwal is to justify his resignation from Delhi's chief ministership to the voters of Varanasi.
"You have only one point against me that I resigned from the post of Delhi chief minister. But I did no corruption whereas Modiji is the agent of Ambani.
"All I have to do is to convince people, and they are getting convinced," Kejriwal told IANS.
"The comparison is between the one who resigned, and the one who is looting the country," he said.
After running the Delhi government for 49 days, Kejriwal and his cabinet quit the government over the defeat of the anti-graft Jan Lokpal bill by the BJP and the Congress in the assembly.
Despite all the challenges in the Hindu holy city, Kejriwal is confident of winning against Modi.
"My political assessment is that the BJP will not get more than 160 seats and Modi will not become prime minister. BJP's president Rajnath is waiting for the right opportunity."