Krsna is called bhakta-vatsala. He is very affectionate towards His devotees. He takes pleasure in being controlled by His devotees. Although Krsna has all good qualities, He is not proud. He drove Arjuna's chariot. Krsna wasn't thinking, what will people think if I drive a chariot? No king would ever lower himself to do such menial service. Krsna's foster father was a chariot driver and for that reason Krsna was not accepted as a ksatriya and was looked down upon. In Draupadi's svayatnvara she rejected him on these grounds. Yet Krsna accepted such a low position to please His devotee. In the battle of Kturuksetra, once when Arjuna's horses became tired he made a hall of arrows and created a lake so that the horses could drink. At that time Krsna took care of the horses by plucking out all the arrows from their body, dressing their wounds, massaging them and giving them water. He performed all the duties of a groom. 
Why did He take so much trouble? – out of His affection for Arjuna. He takes more pleasure in serving His devotee than He does in being served. So we should learn from this that it is better to serve Krsna's servant than to try to serve Him directly. 
Before the battle of Kuruksetra was about to begin, Arjuna ordered Krsna to take his wonderful chariot a little further up ahead so that Arjuna can see who all have come to fight with him. It is a simple instruction. But its Significance lies in the fact that it was administered to none other else than the Supreme Personality of Godhead. 
Although Lord Krsna is the Supreme Personality of Godhead, out of His causeless mercy He was engaged in the service of His friend. He never fails in His affection for His devotees, and thus He is addressed herein as infallible. As charioteer, He had to carry out the orders of Arjuna, and since He did not hesitate to do so, He is addressed as infallible. Although He had accepted the position of a charioteer for His devotee, His supreme position was not challenged. In all circumstances, He is the Supreme Personality of Godhead, Hrisikesa, the Lord of the total senses. The relationship between the Lord and His servitor is very sweet and transcendental. The ser vitor is always ready to rend er service to the Lord, and, similarly, the Lord is always seeking an opportunity to render some service to the devotee. He takes greater pleasure in His pure devotee's assuming the advantageous position of ordering Him than He does in being the giver of orders. Since He is master, eve ryone is under His orders, and no one is above Him to order Him. But when He finds that a pure devotee is ord ering Him, He obt ains transcendental pleasure, although He is the infallible master in all circumstances. 
As a pure devotee of the Lord, Arjuna had no desire to fight with his cousins and brothers, but he was forced to come onto the battlefield by the obstinacy of Duryoohana, who was never agreeable to any peaceful negotiation. Therefore, he was very anxious to see who the leading persons present on the battlefield were. Although there was no question of a peacemaking endeavour on the battlefield, he wanted to see them again, and to see how much they were bent upon demanding an unwanted war. 
One mustn't think that Krsna requires the devotee to serve for any length of time before the benediction of pure devotional service is awarded to him. Surrender to Krsna may take only a moment if the devotee so desires. This is exemplified in the life of Bali Maharaja, who had accepted a spiritual master who was unqualified due to his desires for personal aggrandizement. Bali's master, Sukracarya, guided him to conquer the celestial kingdom of Indra. As Bali did this, the rightful proprietors of the heavenly kingdoms, the demigods headed by Indra, were all chased away. The vanquished demigods, however, were all devotees of the Lord; hence they prayed that He return them to their posts so that they could continue their service of universal administration. In order to answer the prayers of His devotees, the all-auspicious Supreme Personality of Godhead Sri Krsna incarnated Himself as Vamanadeva, a beautifully effulgent brahmana boy who was no larger than a dwarf. He proceeded at once to the kingdom of Bali Maharaja, which rightfully belonged to the demigods. 
When Vamana arrived, Bali Maharaja was most attracted to His extreme beauty. Especially noticeable was Vamana's glowing effulgence. Sukrikarya, Bali's spiritual master, recognized that this dwarflike brahmana must be the Supreme Personality of Godhead. Therefore, knowing that a brahmana approaches the rich for the purpose of begging something from them, he declared to Bali, "Don't give this boy anything!" 
Bali, on the other hand, wanting to offer something, ran forward to the brahmana boy out of spontaneous attraction, declaring that He could have whatever He wanted. Bali was ready to surrender everything, but Lord Vamanadeva declared that since He Himself was a brahmana, He needed only enough land upon which to sleep. A brahmana is very humble in his material needs. Therefore, Lord Vamanadeva requested of him, "Please give Me three steps of land." 
"Is that all You want?" Bali asked. 
"Please ask for whatever You would like."
 Vamanadeva said, "Three steps of land will be enough." 
With that, the Lord took His first step. He expanded Himself into gigantic size with His inconceivable potency, and covered the entire lower and middle planetary systems. Then, expanding to universal size, He took His second step, and with this step the Lord covered the entire heavenly planemry system. He said to Bali Maharaja, "Now I have covered the entire uni verse in two steps. You prom ised to give Me three steps. Where can I put My th ird!" 
Bali Maharaja realized that the inconceivable Lord, the Personality of Godhead, had come to take from him his ill-gotten gains. He surrendered unto the Lord and said, "You may put Your thirdstep on my head, my Lord." The Lord was pleased with Bali's surrender, and placing His lotus foot on Balishead, He benedicted him with pure devotional service. That is the Lord's kindness. Krsna was pleased with Bali 's offering of everything he could give, including his own self. If one rejects all his past nonsense and surrenders unto Him fully, that is called pure devotion. Bali Maharaja, in his surrender, rejected an unqualified spiritual master who was interested only in greedy motivations. For this, Bali Maharaja is called a mahajana, or great devotee of the Lord. 
Lord Yamana, in order to further bless His mahajana devotee, gave him a kingdom in the lower regions of the universe. The Lord is so kind to His pure devotee Bali Maharaja that there, on the planet of Bali Maharaja, He acts as his personal doorman. Whenever someone comes to see the mahajana Bali, the Lord in His four-armed form is there to greet the guest. That is Krsna' s love for His pure devotee who took only a second to surrender. Krsna does not mind offering service to His pure devotee Bali as a doorman, any more than He minds offering to drive the chariot of Arjuna, for the Lord is the servant of His servant. He is attracted by the loving att itude of His devotee. 
(Syamananda Dasa)