"Even during the British rule, the Congress party would not have faced so much adversity that we have gone through in the last 50-60 years," Modi said after he laid the foundation stone of the new party headquarters here.
"Sacrifice of generations of karyakartas (workers) inspire us to work," he said.
Addressing a large gathering of people, including ministers, party leaders and workers, the Prime Minister said the BJP did not even care to keep a record of its activities in the past as the leaders and workers of the party did not pay much attention to it.
"It was not a mistake as they were more concerned about welfare of the people and the work being done in this regard," he said, adding that if one has to look for a picture of Atal Bihari Vajpayee doing something for the people, it will not be found.
Modi said it was the "need of the hour" to keep a record of all that is being done by the party for the country.
"It's need of the hour that everything being done by the party is recorded," Modi said.
"Not many know us in the world. (And those who know us) they know us through what others have said about us," Modi said, urging the party leaders and workers to keep a record of the work of the party.
Talking about how the BJP struggled on its way up, Modi said the party leaders and workers did not abandon its ideology even if they had to sit in the Opposition for years.
He said the BJP, while growing, would find it difficult to hire an office.
It was difficult for the BJP candidates to hire an office in Kolkata during the recently held state assembly elections as anybody willing to give them space would face trouble, Modi said in an apparent attack on the ruling Trinamool Congress in that state.
"The new office is not just a building or a structure but a symbol of the sacrifices of the party leaders," Modi said. "Our determination is to take everyone together, work for everyone. Nation building is our main priority," the Prime Minister noted.
"I think few party candidates lost so many deposits as we did but still that did not affect the determination of our party workers," he added.
He further said that the leadership of the BJP was such that their "thought was clear... we will be in the Opposition but we won't compromise on our ideals".
The new proposed party office building will have 70 rooms on Deen Dayal Upadhyay Marg, which is just 5 km from the current office on Ashoka Road.
The building will be spread across two acres with 70 per cent lush greenery.
