Caitanya Caritamrta—Madhyalila-15.108—- For conditioned souls to do devotional service, deity worship is necessary.
932) Whether I know without purascarya activities, I can’t become perfect! Taught by Srila Prabhupada!
In the Hari-bhakti-viläsa (17.4–5, 7) it is stated:
vinä yena na siddhah syän mantro varsa-satair api
krtena yena labhate sädhako vänchitam phalam
purascarana-sampanno mantro hi phala-dhäyakah
atah puraskriyäm kuryät mantra-vit siddhi-kanksayä
puraskriyä hi mantränäm pradhänam viryam ucyate
virya-hino yathä dehi sarva-karmasu na ksamah
purascarana-hino hi tathä mantrah prakirtitah
“Without performing the purascaryä activities, one cannot become perfect even by chanting this mantra for hundreds of years. But one who has undergone the purascaryä-vidhi process can attain success very easily. If one wishes to perfect his initiation, he must first undergo the purascaryä activities. The purascaryä process is the life force by which one is successful in chanting the mantra. Without the life force, one cannot do anything; similarly, without the life force of purascaryä-vidhi, no mantra can be perfected.” —————————————-