Your blade is keen enough to hew incorporeal creatures.

Prerequisite(s): Base attack bonus +1, Knowledge (religion) 1 rank.

Benefit(s): As a swift action, you can imbue a weapon you wield with spiritual energies for 1 round. An imbued weapon damages incorporeal creatures as though it were magical. If the imbued weapon has an enhancement bonus of +2 or greater, it functions as a ghost touch weapon.

A weapon imbued in this way can deal precision damage (such as sneak attack damage) to incorporeal creatures.