Practicing Krishna Consciousness
Haribol means, "chant the name of the Lord." Bol means to chant or speak. Hari means, "He who steals away the distresses of his devotees and ultimately steals their minds by His excellent transcendental qualities." Praising and chanting is very similar. "Haribol" is comparable to the Christian phrase, "Praise the Lord!" They mean the same thing.
Speaking about Krishna is known as hari-katha—this refers not only to chanting His name—so “Haribol” would also be appropriate encouragement to glorify Him in any number of ways.
Initiated devotees in the Krishna consciousness movement accept new, spiritually focused names in connection with their new spiritual connection.
As with every Krishna conscious practice, there are scriptural explanations as well as very practical, personal explanations.
The foundational principle of Krishna consciousness (or any genuine spiritual path) is that there is a superior identity beyond this material body, commonly known as the soul. This identity has a permanent and unique relationship with Krishna that is completely inseparable.
When the soul desires to try to enjoy independently of Krishna and becomes attracted to this material world, he is covered by ignorance, and becomes forgetful of Krishna, and of his relationship with Krishna.
He misidentifies himself with the temporary body that he's wearing, and falsely thinks that the things related to that body are his. In this condition happiness and distress are gauged by the experience of pain or pleasure in relationship with the body, and the soul constantly endeavors to please the senses of his temporary body.
However, no matter how expertly the soul arranged his material situation, pain and disappointment are always coming. Even though the soul has no desire for distress to come, distress is coming.
Because the soul is covered by ignorance of his eternal position and has no knowledge of how to escape this cycle of temporary happiness and distress, the cycle continues.
All of this distress and entanglement is due to the soul's original misidentification with the body.
The soul wanders through thousands of species in many different universes, constantly baffled in his endeavor to enjoy the material energy.
Naturally the question arises, "How is this soul delivered?"
Only when the soul comes into the association of a genuine spiritual teacher—guru—can his original identity in service to Krishna be awakened.
When the soul associates with and hears the guru's instructions, he develops some desire to serve Krishna and he begins to adopt the practices of bhakti -yoga under the guru's guidance.
When the guru sees that the soul is qualified to become a disciple and fully devote himself to the practice of bhakti-yoga, the guru gives the disciple initiation.
It is common in this practice of initiation that the guru will give a spiritual name to the disciple. So in answer to your question, "how is the name chosen?" the pure guru decides, with inspiration from Krishna what the name of the disciple should be.
But why is it done in the first place?
As I mentioned before, all of the suffering that is experienced by the soul is due to forgetfulness of his original nature and to the misidentification of himself with the body.
Practically, when I hear my name, I think of myself as my body. I identify my birth given name with my family, my friends and other material relationships.
It is common that a son will be named after their father or grandfather etc. Therefore that name is naturally affiliated with material things.
When that soul comes to the shelter of a guru and desires to serve Krishna in a spiritual form, the guru will give that person a name that is aligned with that desire. "Your name is now Krishna Dasa."
Now, when that person speaks or hears his name, there is a different relationship that is brought to consciousness. Rather than thinking of the material designations of his birth given name, he will think of his guru and of his true identity as a servant of Krishna.
When a person accepts spiritual initiation it is known as his second birth, because he is practically taking his first steps into reviving his lost, eternal relationship with Krishna.
Just as at birth a person is named, so at his second birth he is also named. But this time he is given a name like Krishna Dasa (the servant of Krishna) or Bhakta Dasa (the servant of the Vaishnavas).