This is a verse from the Padma Purāṇa. Viṣṇu-bhaktas, or devotees in Kṛṣṇa consciousness, are known as devas (demigods). Atheists, who do not believe in God or who declare themselves God, are asuras (demons). Asuras always engage in atheistic material activities, exploring ways to utilize the resources of matter to enjoy sense gratification. The viṣṇu-bhaktas, Kṛṣṇa conscious devotees, are also active, but their objective is to satisfy the Supreme Personality of Godhead by devotional service. Superficially both classes may appear to work in the same way, but their purposes are completely opposite because of a difference in consciousness. Asuras work for personal sense gratification, whereas devotees work for the satisfaction of the Supreme Lord. Both work conscientiously, but their motives are different.
The Kṛṣṇa consciousness movement is meant for devas, or devotees. Demons cannot take part in Kṛṣṇa conscious activities, nor can devotees in Kṛṣṇa consciousness take part in demoniac activities or work like cats and dogs simply for sense gratification. Such activity does not appeal to those in Kṛṣṇa consciousness. Devotees accept only the bare necessities of life to keep themselves fit to act in Kṛṣṇa consciousness. The balance of their energy is used for developing Kṛṣṇa consciousness, through which one can be transferred to the abode of Kṛṣṇa by always thinking of Him, even at the point of death.