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,
The ultimate goal of Bhakti is to get Krishna and we get it by taking shelter of the holy name.
Krishna is present fully in His holy name and this is realized by the humility and sincerity in our chanting.