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,
Lord Sri Krishna is the complete form of all existence, both material and spiritual.
Srimad Bhagavatam 2.4.13,
Whoever sees Lord Krishna sees a festival. His face and body are fully satisfying for everyone to see.
Srimad Bhagavatam 9.24.65,
The Supreme Personality of Godhead, Krishna, appears in human society as an ordinary human being but acts very uncommonly for the well-being of the entire world.
Srimad Bhagavatam 7.10.70,
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,