Every single door must be knocked on at least once
"Everyone's auspiciousness will come by preaching about Lord Caitanya. Like itinerant merchants you should take the wares of Caitanya-vani throughout the globe. If necessary, go to all four corners of the earth. Violence to oneself and others under the name of nirjana-bhajan must be stopped. Every single door must be knocked on at least once. If the inhabitants sincerely inquire as to which manner of hari-bhajan may be performed aright, tell them that the only way is through the bhaktivinode-dhara, the line of Bhaktivinode Thakur."
[ From an address at the disappearance festival of Srila Thakur Bhaktivinode in 1936. Quoted in Bhaktisiddhanta Vaibhava, volume 1, by Bhakti Vikas Swami. Also in Sri Krishna Kathamrita Bindhu, issue no. 412 ]