Bhagavad-gītā 3.6

There are many pretenders who refuse to work in Kṛṣṇa consciousness but make a show of meditation, while actually dwelling within the mind upon sense enjoyment. Such pretenders may also speak on dry philosophy in order to bluff sophisticated followers, but according to this verse these are the greatest cheaters. For sense enjoyment one can act in any capacity of the social order, but if one follows the rules and regulations of his particular status, he can make gradual progress in purifying his existence. But he who makes a show of being a yogī, while actually searching for the objects of sense gratification, must be called the greatest cheater, even though he sometimes speaks of philosophy. His knowledge has no value because the effects of such a sinful man's knowledge are taken away by the illusory energy of the Lord. Such a pretender's mind is always impure, and therefore his show of yogic meditation has no value whatsoever.