Krsna is Impartial

When Krsna appears in this world, He gives pleasure to His devotees, annihilates demons and establishes the religious principles. In the battle of Kurukshetra and before He always protected Pandavas, His devotees. Without His support they could have never been victorious over powerful Kurus.
This episode may lead to conclusion that Krsna is partial towards His devotees.

But Kunti maharani prays:
"My Lord, I consider Your Lordship to be eternal time, the supreme controller, without beginning and end, the all-pervasive one. In distributing Your mercy, You are equal to everyone. The dissensions between living beings are due to social intercourse." (1.8.28)
"O Lord, no one can understand Your transcendental pastimes, which appear to be human and are so misleading. You have no specific object of favor, nor do You have any object of envy. People only imagine that You are partial." (1.8.29)

Prabhupada compares the mercy of Lord to sun rays. Just like sun does not discriminate in distributing its light and its rays are all pervading. Lord's mercy and love is not only for a certain section of people. Every living entity is an eternal part and parcel of Supreme Being. Every jiva is a son of God. However, apparent partiality is due to the difference in receptacles. Pure devotee of the Lord is cent per cent surrendered unto Him, therefore all the love and protection of the Lord is available for such a fortunate soul. People consider the path of bhakti as the path of flattery. There is a significant difference. In flattery there is an expectation of something in return but bhakti means the devotee has no expectations whatsoever. He is serving the Lord only for His pleasure which is the constitutional position of every living being. He is unmotivated and selfless. To such a surrendered pure soul, Krsna gives Himself not just love. There are others like suffering and needy men, inquisitive persons or philosophers who make temporary connections with the Lord to serve a particular purpose. When the purpose is served, there is no more relation with the Lord. They are like those who expose themselves to sun only for some time. So they will receive only partial sunlight. Obstinate people who are envious of Lord and always rebel against His authority, carry a bowl. Ideally that bowl should be upright so that it can be filled with nectar of Lord's love. But they, misusing their free will, keep it upside down. Therefore, Kunti maharani says, "...The dissensions between living beings are due to social intercourse." and "...People only imagine that You are partial." This means people are suffering or enjoying only due to their own karma. They will receive reactions according to their use of free will.

Therefore, natural conclusion is, as put by Prabhupada, "...Such partiality in receiving the Lord's mercy is relative to the recipient, and it is not due to the partiality of the all-merciful Lord." Krsna also says in Bhagavad Gita, "As you shall approach me so shall I reciprocate." and "I envy no one, nor am I partial to anyone. I am equal to all. But whoever renders service unto Me in devotion is a friend, is in Me, and I am also a friend to him." (BG: 9.29)