"A devotee means, real devotee means, he has no purpose for material gain. That is real devotee. Now we have to see what kind of devotee he is. There are two kinds of devotees: with purpose and without purpose. The 'without purpose' devotee is pure devotee, and 'with purpose' devotee, they are material devotee."
(Srila Prabhupada Conversation, March 1, 1975, Atlanta)