The study of the Vedas is the starting point to any spiritual aspirant. One who follows the Vedic teachings is sure to find ways to fulfil many aspirations in this world and in other worlds as well.
But the knowledge of the Vedas with respect to these matters is far from useful to one whose aim is attainment of Brahma Jnana, is what the Gita reiterates, pointed out Srimati Rukmini Ramamurthy in a discourse. One who lives in a place where there is only a well or a pond will have to be satisfied with the water that is thus available. But by chance if he comes to know that water is available in plenty elsewhere, it is most unlikely that he would settle down for well water alone for his requirement.
By extension, it follows that if one comes to know of the prospect of everlasting bliss that far supersedes all these earthly joys that are after all ephemeral, will he not opt for it? Scriptures try to make an inquiry into the kind of happiness enjoyed by the various classes of beings, whether human or divine. If, for instance, the basic unit of bliss is taken as the earthly happiness enjoyed by one who is young, handsome, learned, healthy, strong of mind, wealthy and has been endowed with all human enjoyments, it is shown that it becomes progressively higher in the various grades of divine beings such as gandharvas, devas, Indra, Bruhaspati, Prajapati and so on. They conclude that the supreme state of bliss that the knowledge of Brahman confers is far superior to what is available or thought of as happiness in human terms. It is beyond the grasp of the mind and the senses and is perfect, complete, infinite and absolute. This is attainable to him who is able to transcend his ignorance of the true nature of happiness.