There are many devotees who assume themselves to be in Krsna consciousness and devotional service but at heart do not accept the Supreme Personality of Godhead, Krsna, as the Absolute Truth. For them, the fruit of devotional service-going back to Godhead-will never be tasted. Similarly, those who are engaged in fruitive, pious activities and who are ultimately hoping to be liberated from this material entanglement will never be successful either because they deride the Supreme Personality of Godhead, Krsna. In other words, persons who mock Krsna are to be understood to be demonic or atheistic. As described in the Seventh Chapter of Bhagavad-gita, such demonic miscreants never surrender to Krsna. Therefore their mental speculations to arrive at the Absolute Truth bring them to the false conclusion that the ordinary living entity and Krsna are one and the same. With such a false conviction, they think that the body of any human being is now simply covered by material nature and that as soon as one is liberated from this material body there is no difference between God and himself. This attempt to become one with Krsna will be baffled because of delusion. Such atheistic and demoniac cultivation of spiritual knowledge is always futile. That is the indication of this verse. For such persons, cultivation of the knowledge in the Vedic literature, like the Vedanta-sutra and the Upanisads, is always baffled.