Karma - manifestation of existence
Action (karma) is the practical or utilitarian side of the manifestation of existence, whereas knowledge is its essential aspect. These two aspects are conjoined with the middle link, which is the human heart. This very heart sends its current in the grosser regions of existence, causes the action to be performed and practiced, and thus arranges for the expression of its existence.
Taken from the book "Truth Eternal (5th edn., 2010)", Chapter "Karma", pg. 86, by Lalaji Maharaj