[Bhagavata-dharma, the principles of religion] is understandable if one follows the parampara system of Lord Brahma, Lord Siva, the four Kumaras and the other standard authorities. There are four lines of disciplic succession: one from Lord Brahma, one from Lord Siva, one from Laksmi, the goddess of fortune, and one from the Kumaras. The disciplic succession from Lord Brahma is called the Brahma-sampradaya, the succession from Lord Siva (Sambhu) is called the Rudra-sampradaya, the one from the goddess of fortune, Laksmiji, is called the Sri-sampradaya, and the one from the Kumaras is called the Kumara-sampradaya. One must take shelter of one of these four sampradayas in order to understand
the most confidential religious system. In the Padma Purana it is said, sampradaya-vihina ye mantras te nisphala matah: if one does not follow the four recognized disciplic successions, his mantra or initiation is useless. In the present day there are many apa-sampradayas, or sampradayas which are not bona fide, which have no link to authorities like Lord Brahma, Lord Siva, the Kumaras or Laksmi. People are misguided by such sampradayas. The sastras say that being initiated in such a sampradaya is a useless waste of time, for it will never enable one to understand the real religious principles.

Srila Prabhupada, Srimad-Bhagavatam 6.3.20-21 purport