- The depth of our love for the Tzaddik in his lifetime and after his death draws down his midot (love of God, fear of God, and pure Faith (emunah) in God) to be clothed within our own minds so that we too can act with these same attributes as we are now able to grasp and understand what we were previously only able to observe from a distance through the Tzaddik's actions and words.
- When we implement the Tzaddik's lessons in our lives, the light of the Tzaddik shines down upon us, encompassing us, and this inspires us to true teshuvah and divine service.
These are the two general ways the Tzaddik lives on with us even after he has (for the most part) left this world and moved on to the stages that come after life here, as described in the Zohar and explained here by the first Lubavitcher Rebbe in the Tanya, section four, 27th letter.
It seems to me that there is a clear microcosmic example here of our interaction with God: As the Baal HaTanya explains, God both permeates all of creation and ecompasses it. In a more limited sense, the effect a Tzaddik has on our lives is also described in these two ways, one that permeates our minds and one that encompasses them.
[We learned this letter this past Shabbath in the memory (לע"נ) of my father in law, HaRav Meir Benayahu ben HaRav Yitzhak Nissim, ztz"l]