Krishna does not need anyone's help, including Arjuna's, to fulfill his mission of destroying the Kaurava army, as he has already destroyed them. However, out of his causeless mercy, he allows his devotees to assist him in order to give them the opportunity to serve him. Just as Lord Rama took the help of monkey soldiers to build a bridge and defeat Ravana even though he did not need assistance, Krishna is giving Arjuna the chance to serve him by fighting, even though Krishna himself does not need Arjuna's help. A story is told of a Guru explaining to a historian that human efforts, while they appear to change the course of events, are

1. STANDARD
IX
CHAPTER 11
THE UNIVERSAL FORM
Only throughdivineeyes of devotion, you can see Krishna
Lesson-02
IS KRISHNA DEPENDENT ON ARJUNA FOR HIS WORK?
Krishna is saying to Arjuna: “Just be My instrument - I
have already destroyed them.” Krishna does not need
anyone’s help in fulfilling His mission. Still out of His
causeless mercy He allows His dear devotees to assist
Him and thus gives them opportunityto serve. When Lord
Rama appeared, He did not need the assistance of monkey
soldiers to build the bridge or kill Ravana, but He took
assistance just to give opportunityof service.
Similarly, Krishna does not need assistance of anyone to
kill all the kaurava army. In childhood,He killed many
ferocious demons single-handedly. But here, He is giving
Arjuna a chance to serve Him. Krishna always wants to
give credit to His devotees. That is one of Krishna’s
opulencecalled “renunciation”.

2. There is nice story regarding this point.
We are just instruments
The visiting historian was disposed to be argumentative.
"Do not our efforts change the course of human history?"
he demanded.
"Oh yes, they do," said the Guru.
"And have not our human labors changed the earth?"
"They certainly have," said the Guru.
"Then why do you teach that human effort is of little
consequence?"
Said the Guru, "Because when the wind subsides, the
leaves still fall."
MORAL: The leaves will fall by the will of Lord
irrespectiveof whether wind is presentor not. Similarly
all the Lord’s desires areautomaticallyand infallibly
fulfilled. If someonedoes not agreeto be instrument,
someoneelse will. So even if Arjuna does not fight,
Krishnawill have the miscreantskillednonetheless. So
Arjuna shouldserve as an instrumentto pleaseKrishna,
becausethat is the purposeof everyone’slife – to please
Krishna.
Knowing that we are just instruments does not mean that
we become relax in our service to Krishna. While doing
service to Krishna we should do it in a mood that “I am
responsiblefor the service so let me put my best.” But at

3. the same time, we should be mindful that we are just
instruments in Krishna’s hands.