Vijnana Bhairava Tantra

16: That should, in verity, be known as His essential nature, immaculate (vimalam) and inclusive of the entire universe (visvapuranam). Such being the state of the highest Reality, who can be the object of worship, who is to be satisfied with worship.
17: That niskala state of Bhairava which is celebrated in this way is alone the highest state. That is declared as para devi, the highest goddess, para or highest not only in name, but because that is actually her highest form (pararupena).
18: Since there is always non-difference between Sakti and possessor of sakti, therefore being endowed with His attributes Sakti becomes the bearer of the same attributes. Therefore being non-different from para (the highest i.e. Bhairava) she is known as para (the highest i.e. Bhairavi).
19: The burning power of fire is not accepted as separate from fire even after full consideration. Even so the Parasakti is not separate from Bhairava. Only it is described in a distinct way as a preliminary step for the listener towards its knowledge.
20: When in one who enters the state of Sakti, there ensues the feeling of non-distinction between Sakti and Siva, then he acquires the state of Siva, for in the agamas (iha), she Sakti is declared as the door of entrance into Siva. Literally, Sakti is like Siva's face.