The other day I was talking with one guest, explaining that we are actually sac-cid-ānanda; (eternal, full of knowledge, and bliss), eternal spirit souls, but are, at the present moment, in a temporary position, just like a fish out of water. This is a very good analogy that Srila Prabhupada has used often in his preaching. I did a search this morning on Prabhupada Books.com and found a few references that I am posting here, as well as one very nice Bhagavad-gita Lecture wherein Srila Prabhupada is describing the nature of the soul.
Everyone in the material world is engaged in all kinds of political, philanthropic and humanitarian activities to make material life happy and prosperous, but this is not possible. One should understand that in the material world, however one may try to make adjustments, he cannot be happy. To cite an example I have given many times, if you take a fish out of water, you can give it a very comfortable velvet bedstead, but still the fish cannot be happy; it will die. Because the fish is an animal of the water, it cannot be happy without water. Similarly, we are all spirit soul; unless we are in spiritual life or in the spiritual world, we cannot be happy. That is our position. (Srila Prabhupada; Krsna Consciousness The Topmost Yoga System)
Śrīla Prabhupāda: The Vedic injunction is that people are searching after knowledge, and that when one understands the Absolute Truth, he understands everything. Yasmin vijñāte sarvam evaṁ vijñātaṁ bhavati. People are trying to approach an objective, but they do not know that the final objective is Kṛṣṇa. They are simply trying to make adjustments with so many materialistic revolutions. They have no knowledge that they are spiritual beings and that unless they go back to the spiritual world and associate with the Supreme Spirit, God, there is no question of happiness. We are like fish out of water. Just as a fish cannot be happy unless he is in the water, we cannot be happy apart from the spiritual world. We are part and parcel of the Supreme Spirit, Kṛṣṇa, but we have left His association and fallen from the spiritual world because of our desire to enjoy this material world. So unless we reawaken the understanding of our spiritual position and go back home to the spiritual world, we can never be happy. We can go on theorizing for many lifetimes, but we will only see one revolution after another. The old order changes, yielding its place to the new. Or in other words, history repeats itself. (Srila Prabhupada; The Journey for Self Discovery)
A fish that is taken out of the water cannot be happy by any arrangement on land. He must be supplied with water. In the same way, the minute sac-cid-ānanda living entity cannot be really happy through any amount of planning conceived by his illusioned brain in this material universe. He must therefore be given a different type of happiness which is spiritual in essence. Our ambition should be aimed at enjoying spiritual bliss and not this temporary happiness. Some philosophers claim that spiritual bliss is attained by negating material happiness and material existence. Theoretical negation of material activities as propounded by Śrīpāda Śaṅkarācārya may be effective for an insignificant section of mankind, but the best and surest way for everyone to attain spiritual bliss was propounded by Lord Śrī Caitanya Mahāprabhu by means of devotional activities. These devotional activities can change the very face of material nature. (Srila Prabhupada; Elevation to Krsna Consciousness)