Devotee (4): What is the proper relationship of the devotee to Rādhā, Rādhikā?
Prabhupāda: Rādhārāṇī is daivī-māyā. Just like we are, in our material conditional life, we are under the material energy. Similarly, in our liberated state we have to become under the spiritual energy. That spiritual energy is Rādhārāṇī. We are acting at the present moment under material energy, because our body is made of material energy. So when you are liberated you will develop your body of spiritual energy. That spiritual energy is Rādhārāṇī. So you have to become under some..., under the control of some energy. You are also energy; you are marginal energy. Marginal energy means you may be under the control of the spiritual energy or you may be under the control of material energy—your marginal position. But when you are under the control of the material energy, that is your precarious condition, struggle for existence. And when you are under spiritual energy, that is your life of freedom. Rādhārāṇī is spiritual energy, and Durgā, or Kālī, is material energy. So those who are materialist, they worship Drgā, Kālī, the material, different forms of material energy. And, so in both the cases... There is a word in Sanskrit, it is called śakta, śakta. Śakta, the word comes from śakti. Śakti means energy.
Introduction to Bhagavad-gita As It Is -- Los Angeles, November 23, 1968