Addressing the national council of the Bharatiya Janata Party, Advani said there should be no slackness in the efforts to return to power after a decade's break.
"One of the reasons for losing the 2004 Lok Sabha polls was over confidence," he said.
"We should not be over confident and there should not be any shortcoming in the hard work that has to be put in."
One of the reasons for losing the 2004 LS polls was over confidence: Advani
Advani added that he wanted to address the lack of trust in the BJP among the Muslim community.
"They know they have been used for votes, and no one did anything for them.
"Our party believes in integral humanism... We do not discriminate on the basis of religion, caste or language.
"Those who talk about majority and minority are those who want their votes. We want to work for everyone."
Saying he had never seen the party brimming with such confidence, Advani thanked BJP president Rajnath Singh for naming Gujarat Chief Minister Narendra Modi as the prime ministerial candidate.
"I want to thank the party president for his confidence that we will get a majority (in the Lok Sabha) and for announcing Modi as the prime ministerial candidate."