Living beings who are entangled in the complicated meshes of birth and death can be freed immediately by even unconsciously chanting the holy name of Krishna, which is feared by fear personified. — Srimad Bhagavatam, 01.01.15.
The holy name of Krishna is so attractive that anyone who chants it — including all living entities, moving and nonmoving, and even Lord Krishna Himself — becomes imbued with love of Krishna. This is the effect of chanting the Hare Krishna maha-mantra.
Chaitanya Caritamrta, Antya Lila 3.268,
It is said, kali-kale nama-rupe krishna-avatara: Krishna descends in this Kali-yuga in the form of His holy name — Hare Krishna, Hare Rama.
Srimad Bhagavatam 9.10.53,
Cut the Anarthas with Scissor of Holy names of the Lord.
The ultimate goal of Bhakti is to get Krishna and we get it by taking shelter of the holy name.
Prabhupada: Ceto-darpana-marjanam [Cc. Antya 20.12]. And then bhava-maha-davagni… Then his material pangs will be over. This is the only medicine. Therefore chant Hare Krsna. Some way or other, let them have the chance of hearing, and then it will act as medicine