"There is no more higher exalted devotees than the gopis. Therefore Caitanya Mahaprabhu recommended that the gopis, ramya kacid upasana vraja-vadhu-vargena ya kalpita. There is no better type of worshiping Krishna than the method by which gopis worship Krishna. They, their love was so intense that they did not care for any family, any honor, or any prestige -- nothing. That is the highest, topmost loving stage of Krishna. And Krishna also loved the gopis, so much so that Krishna asked them that 'You cannot expect any return from Me for your ecstatic love. I cannot give you. It is beyond My power.' So they purchased Krishna. And the topmost gopi is Radharani. So we should not consider these gopis' dealings with Krishna as ordinary material dealings. It is not that. Ananda-cinmaya-rasa-pratibhavitabhis tabhir ya eva nija-rupataya kalabhih. The gopis are expansion of Krishna's pleasure potency. That is described by Srila Jiva Gosvami. Radha krsna-pranaya-vikrtir hladini-saktir asmat. Hladini-sakti. Krishna has got the pleasure potency. Parasya saktir vividhaiva sruyate. He has got multi-energies. In the Visnu Purana it is also said, parasya brahmanah saktis tathedam akhilam jagat. Whatever we see, that is display of the potencies, different potencies of the Supreme Personality of Godhead. Just like the sun is ninety-three millions of miles away from this earthly planet. Still we are getting heat and light energy of the sun. Goloka eva nivasaty akhilatma-bhutah [Bs. 5.37]. That is Krishna's energy. Although He is in the Goloka planet, which is the topmost planet in the spiritual world... You cannot estimate the how far the spiritual world is from this material world. From material calculation they say it takes about some forty thousands of years to go to the limit of this universe. Then beyond that universe there is the spiritual world. Paras tasmat tu bhavo 'nyah [Bg. 8.20], another nature, avyakto 'vyaktat sanatanah. Then you pass through the spiritual world, brahmajyoti. There are innumerable, unlimited number of Vaikuntha planets. Then, above all of them, there is the planet Goloka Vrndavana, where Krishna resides."
(Srila Prabhupada lecture, Vrndavana, September 13, 1976)