Caitanya Caritamrta on Progressing in Spiritual Life in Different Yugas: For progress in spiritual life, the sastras recommend meditation in Satya-yuga, sacrifice for the satisfaction of Lord Visnu in Treta-yuga and gorgeous worship of the Lord in the temple in Dvapara-yuga, but in the Age of Kali one can achieve spiritual progress only by chanting the holy name of the Lord.
Purport on Caitanya Caritamrta Adi Lila 7.76
