SB 3.29.7

Pure devotional service in Krsna consciousness is one because in pure devotional service there is no demand from the devotee to be fulfilled by the Lord. Generally people take to devotional service with a purpose. As it is stated in the Bhagavad-gita that people who are not purified take to devotional service with four purposes. A person who is distressed on material condition, if he is a…, is a devotee of the Lord, approaches the Lord for mitigation of his distressed condition. If a person is in need of some money, he also approaches the Lord for asking to get some improvement in monetary condition. And sometimes others who are not in distressed condition or in need of monetary assistance but are seeking knowledge to understand the Absolute Truth, they also take to devotional service. And general inquirer to understand what is the nature of the Supreme Lord, sometimes they also take to devotional service. That is very nicely described in the Bhagavad-gita [Bg 7.16]. Actually the path of devotional service is one without second, but according to the devotees' condition, the devotional service appears to be different and multifarious, as they will be nicely explained in the following verses.