Chanting equally powerful in all ages and especially powerful in this age

Simply by chanting the holy name of the Lord, one advances perfectly in spiritual life. This is the best process for success in life. In other ages, the chanting of the holy name is equally powerful, but especially in this age, Kali-yuga, it is most powerful. Kirtanad eva Krishnasya mukta-sangah param vrajet: simply by chanting the holy name of Krishna, one is liberated and returns home, back to Godhead. Therefore, even if one is able to perform other processes of devotional service, one must adopt the chanting of the holy name as the principal method of advancing in spiritual life. Yajnaih sankirtana-prayair yajanti hi sumedhasah: those who are very sharp in their intelligence should adopt this process of chanting the holy names of the Lord.

Srimad Bhagavatam 7.5.23-24 purport