It is said that He descends in His
original form to only one place of all the millions of planets in the
material universe and that is Bhuvaraloka, our Earth planet. We are
therefore extremely fortunate to have been born in the same kalpa as Sri
Krishna and on the same planet on which He performed His pastimes just 5,000
years ago.
We can to this day visit the birthsite of Sri Krishna in Mathura about 90
miles south of New Delhi, India. We can also go to Vraja, an area that
includes Mathura, Vrindavan, Gokul, Nandagram, etc., where Sri Krishna
performed His childhood pastimes with the cowherd boys (gopas) and damsels
(gopis). So holy is the land of Vraja, that simply living there is
considered to be the greatest of devotional service, and if a devotee is
fortunate to give up his body in this holy land, he is assured of going back
home, back to Godhead.
Krishna descended in an answer to the prayers by Bhudevi, Mother Earth
personified, to relieve her of the burden of innumerable asuras (demons),
who had taken birth as kings and were ruling tyrannically. Actually Sri
Krishna has nothing to do with non-devotees. They all eventually destroy
themselves by their own karmic reactions. But, Sri Krishna always has the
welfare of His devotees in His heart. Just as He always resides in the
hearts of His devotees, His devotees are always there in His heart. and, it
was to give protection to His devotees and establish religiosity that
Krishna descends. He comes to enjoy His pastimes in the association of His
devotees and give them the pleasure of His own association.

When Krishna descended, every one knew He was the Supreme Personality of
Godhead, unlike His later descent as Caitanya Mahaprabhu about 500 years ago
which is called a "gupta" (confidential) avatar, where in He came
in the guise of His own devotee and His identity was only known by a very
few intimate associates. However Sri Krishna came as the performer of super
human activities. When he was just a child of 6 months He killed the
powerful demoness Putna and as a boy of just 6 years old He lifted the
Govardhana hill on His little finger. But the people of Vraja were so
immersed in the love of Krishna, that they were never awed by His opulences
as God. For them He was their son or friend or master, and that was all that
mattered. The Gopis of Vraja were the highest of His devotees who had
crossed all stages of sadhna-vaidhi bhakti and reached a stage where they
knew nothing but the spontaneous love for Krishna. Such a stage is very
exalted and reached by a very few devotees.
It is impossible for non-devotees to even approach Sri Krishna. Many people
try to rationalize or worse, emulate the activities of Krishna. Such people
as destined to fall in the darkest of nescience. Even elevated personalities
like Lord Brahma cannot approach Sri Krishna by dint of mental speculation.
There is only one way to approach Him, and that is in the mood of a devotee,
one of complete surrender, love and service. When Krishna is pleased with
surrender of a devotee, He gives him the benediction of pure devotional
service by which the devotee freed from the illusory energy of maya,
transcends the glaring effulgence of the impersonal Brahamajyoti emanating
from Krishna and can eternally associate with Him personally.
Just as the devotees of Krishna, covered by His internal spiritual potency
called Yogamaya, are able to relish His association; the demons who were
envious of Sri Krishna, come under His external, illusory potency called
Maya, and are never able to approach Him. Jarasandha with his army of
millions of soldiers was defeated 17 times by Krishna and Balarama alone,
but he never accepted Their supremacy. Similarly Kansa, Shishupala, Shalva,
Rukmi - all had witnessed the transcendental activities of Krishna, but out
of their envy and pride they chose to be illusioned and continued to plan to
kill Krishna, till their own very end.

In Bhagavad Gita (4.9), Sri Krishna says One who knows the
transcendental nature of My appearance and activities does not, upon leaving
the body, take his birth again in this material world, but attains My
eternal abode, O Arjuna. So Krishna is not without activity, in fact
He is sac-cit-andanda-vigraha - full of eternal truth, knowledge and bliss
in a personal form. But His activities are mysterious for mundane people. In
fact Sri Krishna Himself says ( BG 9.11) that Fools deride Me when I
descend in the human form. They do not know My transcendental nature and My
supreme dominion over all that be.
So if we are serious about our spiritual lives, then we must hear and read
about the pastimes of Krishna from a self-realized, bona fide source.
Krishna katha is words spoken by Krishna (as in the Bhagavad Gita), and
words spoken about Krishna (as in Srimad Bhagavatam). Both are
transcendental and can liberate one from the cycle of birth and death.
However, just as milk that has been tasted by a serpent is poison, Krishna
katha delivered by materialistic people and professional reciters is
devastating to spiritual progress. We must therefore seek out a
self-realized spiritual master in a bona fide disciplic succession, render
service to him, inquire submissively from him, and try and understand the
glories of Sri Krishna from him.