Bhagavad-gītā 4.31

Whatever form of material existence one is in, one is invariably ignorant of his real situation. In other words, existence in the material world is due to the multiple reactions to our sinful lives. Ignorance is the cause of sinful life, and sinful life is the cause of one's dragging on in material existence. The human form of life is the only loophole by which one may get out of this entanglement. The Vedas, therefore, give us a chance for escape by pointing out the paths of religion, economic comfort, regulated sense gratification and, at last, the means to get out of the miserable condition entirely. The path of religion, or the different kinds of sacrifice recommended above, automatically solves our economic problems. By performance of yajña we can have enough food, enough milk, etc.—even if there is a so-called increase of population. When the body is fully supplied, naturally the next stage is to satisfy the senses. The Vedas prescribe, therefore, sacred marriage for regulated sense gratification. Thereby one is gradually elevated to the platform of release from material bondage, and the highest perfection of liberated life is to associate with the Supreme Lord. Perfection is achieved by performance of yajña (sacrifice), as described above. Now, if a person is not inclined to perform yajña according to the Vedas, how can he expect a happy life? There are different grades of material comforts in different heavenly planets, and in all cases there is immense happiness for persons engaged in different kinds of yajña. But the highest kind of happiness that a man can achieve is to be promoted to the spiritual planets by practice of Kṛṣṇa consciousness. A life of Kṛṣṇa consciousness is therefore the solution to all the problems of material existence.