In the Bhagavad Gita, Bhagavan SriKrishna says:
समोऽहं सर्वभूतेषु न मे द्वेष्योऽस्ति न प्रिय: ।
ये भजन्ति तु मां भक्त्या मयि ते तेषु चाप्यहम् ॥ 29॥
I am equally disposed to all living beings; I am neither inimical nor partial to anyone. But the devotees who worship Me with love reside in Me, and I reside in them.
[BhagavadGita, Chapter 9, Shloka 29]
So, Krishna is equal to everyone. Nobody is a favorite to Him, and nobody is an enemy to Him. Krishna blesses His devotees as per their nature. For the people who devote themselves to Him, He blesses them, gives them the true knowledge, and grants them salvation. For the people who are more into the material world and forget Krishna, they suffer in the cycle of birth and death endlessly. And the people who hate Krishna are sent to Naraka, or even worse, Andha Tamas, named hell, which is the eternal hell.
Here, both the Gopikas and the Pandavas are Krishna Bhaktas and are noble by nature, and are devatas. So, you might be thinking: why did Krishna show partiality by leaving the Gopis and going to the Pandavas? Were the Pandavas so dear to Krishna that He left the Gopis who loved Him more than their own lives? So, let me tell you, there is no such thing. Krishna appeared on this earth for the reduction of the burden on the earth.
The Bhagavata says that Mother Earth was suffering from the burden. Which burden? The burden of people who hated Bhagavan Vishnu, Mother Earth’s husband. No Pativrataa wife can bear her husband’s insult. Plus, the demons had incarnated on the earth in the form of oppressive kings. For example, Kalanemi incarnated as Kamsa; Viprachitti, named Asura, incarnated as Jarasandha; this Jarasandha had his akshouhini sainya, which were demons. Narakasura was there; mainly, Kali Purusha had incarnated as Duryodhana; Indrajit had incarnated as Dushasana; the presiding demon of atheism named Dwapara incarnated as Shakuni. There were different asuras like Pootana, Shakatasura, Trunavarta, Vatsasura, Bakasura, another Bakasura (whom Bheemasena killed), Dhenukasura, Keshi, Vyomasura, Arishtasura, Aghasura, Hamsa and Dibhika, Shishipaala, Dantavakra, Saalva, and 98 Kauravas except Duryodhana and Dushasana, and many more.
So, all these were a burden on the earth. So, Mother Earth assumed the form of a cow and went to Lord Brahma. Lord Brahma and Bhudevi (Mother Earth), along with Lord Shiva and other devatas, went to the Kshirasaagara’s coast and sat there. There, Lord Brahma sat down and did penance and contemplated on Lord Vishnu. All devatas praised the Bhagavan with Vedic hymns like the Purusha Sukta, and so on.
Finally, Bhagavan was pleased by them, and His voice came, which was clearly audible only to Lord Brahma. Lord Vishnu assured the devatas that He would be incarnating to reduce the burden of the earth. So, He incarnated as the eighth son of Devaki and Vasudeva. So, the main objective of Krishna’s incarnation was to end the evil people and to protect and give happiness to the noble people.
Everyone had booked their seats to participate in the Krishna leela. Devaki and Vasudeva were Aditidevi and Sage Kashyapa, who had done penance to get Krishna as their son. So, Krishna appeared as their son. Yashoda and Nandagopa were Dharanidevi (the presiding deity for all tirtha kshetras), and Drona named Vasu. So, both of them had done penance to get Krishna as their child. And hence, Krishna came to Gokula to be the beloved child of Yashoda and Nandagopa.
The Gopikas were Apsara Strees who had done penance to get Krishna’s angasanga, even before His upanayana or thread ceremony. In that too, Neela, the daughter of Kumbhaka (brother of Yashoda), had done penance to marry Krishna and become His first wife even before His upanayana. So, as per their wishes, Krishna gave happiness and fulfilled their wishes by performing Raasakreeda, Jalakreeda, and Naukakreeda (boat riding) with them.
After their wishes were fulfilled, Krishna went to Mathura, killed Kamsa, and then started the further leela of reducing the burden of the earth. Already He had started that mission from the very beginning as a baby by killing Pootana, and then the other demons sent by Kamsa. And even the devatas like Yama Dharmaraja, Mukhyaprana Vayudeva, Indra, and Ashvini Devatas had incarnated as the Pandavas. Mukhyaprana’s wife Bharatidevi had incarnated as Draupadi, and Ramayana’s trijata had incarnated as Subhadra. Yama Dharmaraja had incarnated again as Vidura; the Yadavas were the devatas. Leave all these; Saakshaat Mahalakshmi Devi, the greatest devotee of Krishna, had incarnated in Vidarbha as Rukmini and as the daughter of King Satrajita as Devi Saatraajiti (Satyabhama). All these were also waiting for Krishna. So, Krishna also had to go there.
If Krishna wouldn’t go there, then their births would be wasted. They wouldn’t get the bhaagya of doing seva to the Supreme Bhagavan, who is worshipped by great Gods like Brahma and Shiva. The Pandavas contributed to Krishna’s mission in reducing the burden of earth. Out of these, Bheemasena and Arjuna contributed a lot to doing the Bhu Bhaara Harana (reducing the burden of the earth). Bheemasena killed a lot of demons like Bakasura in Ekachakranagara, Hidimbasura, Jarasandha, Kirmeera, Manimanta, and other Krodhavasha demons; Jatasura during the Vanavaasa; Keechaka in Agyaata vaasa; the 100 sons of Gandhari, along with Duryodhana and Dushasana. Arjuna also killed major demons like Nivatakavachas and the Kalakeyas. He killed Jayadratha, Karna, etc. So, all this was possible because of the shuddha neeti of Krishna and the power of Bheemasena and Arjuna.
So, all this was possible because of Krishna’s neeti. Already, Krishna had killed Pootana, Shakatasura, Trinavarta, Vatsasura, Bakasura, Dhenukasura, Keshi, Arishtasura, Aghasura, Vyomasura, Ugrasura, Shankhachooda, Pralambasura, Chanura, Mushtika, Kamsa, his 11 brothers, Kaalayavana, Jarasandhas, and Akshouhini sainya 18 times, Srugaala Vaasudeva, Shatadhanva, the 7 bulls of King Nagnajit, who were demons in the disguise of bulls. After that, He married Neela or Nagnajiti. After that, Murasura, Narakasura, defeated Banasura and his army, Shishupaala, Saalva, and all. So, He made the Pandavas contribute to the Bhu Bhaara Harana. It is as if He had left the rest as the prasaada for the Pandavas, so that they could contribute to the Bhu Bhaara Harana of Krishna. Plus, to contribute, they also required Krishna’s neeti. Plus, the Pandavas were in trouble and were His cousins. So, to help them, He had to go to them.
Talking about the Gopikas, their love for Krishna was immense. They used to do Bhakti in Krishna by singing about His pastimes, what He did, where He sat, and what He ate. Every second, they thought of Krishna. Indeed, these Gopikas were great personalities. During the Raasakreeda, Krishna does vihaara with the Gopikas. The Gopikas grew arrogant, thinking, ‘Nobody is as lucky as us to get Krishna besides us. We are the best women in the whole universe.’
And noticing this, Krishna disappeared. The Gopikas, in the viraha of Krishna, cried sweetly, and their cry seemed as if a cuckoo was cooing. They sang in praise of Krishna, and finally, responding to their desperate desire to see Krishna and their devotion, Krishna appeared in front of them. The Gopikas came near Him. Some Gopikas saw Him with love; some stared at Him. Some were very angry upon seeing Him, and some were overjoyed and cried in His love. The Gopikas asked Krishna, ‘Why did you disappear?’ Krishna smiled and said, “When you don’t have something which you want desperately, you then know the value of the thing. But when that thing comes near you, you don’t realize the value of it. I want you to increase your love and devotion for me even more.”
The main thing is, why did Krishna leave them in Vrindavan? Because their Bhakti kaarya wasn’t complete, even though their Bhakti was complete. He wanted them to do more Bhakti of His saakaara Krishna roopa, because the more you do Bhakti for Krishna, the more you come near Him. And when Krishna is away, we get to know the value of Krishna and would be more desperate and devoted to meet Krishna. And in this way, when their Bhakti was complete, Krishna granted them Moksha.
What Krishna needs from us is not material wealth or anything, because He has everything. Nothing is in the world that He doesn’t have. He just wants your devotion. Without devotion, if you even offer pancha bhakshya paramaanna to Krishna, like how Duryodhana did, Krishna won’t even look at it; tasting it is too far. And with devotion, even if you offer a glass of milk as Vidura did, Krishna would happily accept it and would grant you even Moksha.
Here, people also have a misconception that there are two Krishnas. One remained in the Vrindavana, and another went to Mathura. Nothing such happened, as per the Bhagavata Purana, and that misconception is wrong. Sri Madhvacharya also doesn’t mention it anywhere in the Mahabharata Tatparya Nirnaya or the Bhagavata Tatparya Nirnaya, and it is also not acceptable to Krishna. The same Krishna, who did Raasaleela with the Gopikas, went to Mathura and killed Kamsa, married Rukmini and Satyabhama, and helped the Pandavas in winning against the Kauravas.
Yeah, Krishna always has His sannidhana in Vrindavana. There is no need to posit two different Krishnas, one remaining in Vrindavana and another travelling to Mathura. The very same Supreme Krishna performed all these lilas. So, the Dwarakadheesha Rukmini-Satyabhama pati Krishna is the same as the Vrindavana Gopikavallabha Yashodanandana Krishna.
No difference at all. Bhagavan Krishna is akhanda and is full of aishvarya and maadhurya every time, be it even if He is in Vraja, or He is in Dwaraka, or in Kurukshetra, holding the rope of the chariot. And Aishvarya doesn’t mean just opulence, but also knowledge, valor, strength, and beauty, also. And even as Lakshminarayana, He has maadhurya, because He is paripoorna of all the gunas every time and in every second. So, one must never do bheda in the avataras or roopas of Bhagavan, or else it is counted as one of the nine forms of hatred in Bhagavan, as stated by SriMadhvacharya.
Hope this helps!
Jay SriRam!
ShriKrishnarpanamastu!