"The great danger of conversion in all ages has been that when the religion of the high mind is offered to the lower mind, the lower mind, feeling its fascination without understanding it, and being incapable of rising to it, drags it down to its level by degrading it." George Bernard Shaw
This is why H.D A.C Bhaktivedanta Swami Srila Prabhupad instructed his initiated disciples to read his books, avoid the ten offenses, follow strictly the four regulating principles, chant a prescribed number of holy names daily and to never forget Krishna.
It certainly true that the holy name alone can elevate one to the highest position of god realization but some regulation will help the aspirant to continue the purification process which will enable him to enter the transcendental realm of pure devotion.
"If with a pleasing attitude any person chants the holy name of Govinda, he is glorified and purified, and his chanting helps the whole world attain liberation." Laghu-bhagavatamrita
Just as watering the root of a tree nourishes the entire tree, in the same way by glorifying the supreme personality godhead the entire world is benefited. Chanting the holy name is devotional service !
"As stated in Srimad-Bhagavatam (7.5.23), there are nine kinds of devotional service: hearing (sravanam), chanting (kirtanam), remembering (visnoh smaranam), serving (pada-sevanam), worship of the Deity (arcanam), praying (vandanam), carrying out orders (dasyam), serving Him as a friend (sakhyam) and sacrificing everything for the Lord (atma-nivedanam). Although each process appears distinct, when one is situated on the absolute platform he can see that they are identical. For instance, hearing is as good as chanting, and remembering is as good as chanting or hearing. Similarly, engaging in Deity worship is as good as chanting, hearing or remembering. The devotee is expected to accept all nine processes of devotional service, but even if only one process is properly executed, he can still attain the highest position (pure devotion) and go back home, back to Godhead."