The only religious principle in the age of Kali is the chanting of the holy name:
[Isvara Puri to Lord Caitanya]:
" 'In this age of Kali there is no other religious principle than the chanting of the holy name, which is the essence of all Vedic hymns. This is the purport of all scriptures.' "
¯Sri Caitanya−caritamrta Adi−lila 7.74
In Kali−yuga, chanting of the holy name is the most feasible means of salvation:
In great jubilation, Sri Caitanya Mahaprabhu said, "My clear Svarupa Damodara and Ramananda Raya, know from Me that chanting of the holy names is the most feasible means of salvation in this age of Kali."
¯Sri Caitanya−caritamrta Antya−lila 20.8
The universal religious practice for the Kali−yuga is the chanting of the holy name:
The religious practice for the age of Kali is to broadcast the glories of the holy name. Only for this purpose has the Lord, in a yellow color, descended as Lord Caitanya. In this age of Kali the practical system of religion for everyone is the chanting of the name of Godhead. This was introduced in this age by Lord Caitanya. Bhakti−yoga actually begins with the chanting of the holy name, as confirmed by Madhvacarya in his commentary on the Mundaka Upanisad. He quotes this verse from the Narayana−samhita:
dvapariyair janair visnuh
pancaratrais tu kevalaih
kalau tu nama−matrena
pujyate bhagavan harih
"In the Dvapara−yuga people should worship Lord Visnu only by the regulative principles of the Narada−pancaratra and other such authorized books. In the age of Kali, however, people should simply chant the holy names of the Supreme Personality of Godhead."
¯Sri Caitanya−caritamrta Adi−lila 3.40