Q: I am not a
religious man, but I am still interested to know if there is such a
concept as mitzvah in Kabbalah as well?
A: Man’s soul
is comprised of 613 desires. The correction of each of those desires
‘for the Creator’ is called “mitzvah”, a “spiritual mitzvah”. All
the spiritual mitzvot, without exception, are laws that operate only
in the spiritual world, not in ours. In our world there are only
corporeal laws, the laws of nature ‘for myself’. The whole point in
the spiritual existence is in the correction of a certain desire –
to become a desire with an aim ‘for the Creator’. But in our world,
a world of will to receive for ourselves alone, the aim ‘for the
Creator’ is absent. Instead, there is work only on the body, and not
inside the will.
(from Kabbalah World Center - "The Kabbalah Experience" - Chapter 12)