It has to come from the core, but we are not masters over that place.
We can barely master our wardrobe—our conscious thought, our words to others, what our hands and feet are doing. Never mind the hidden things within.
But we can do this: We can wash our clothes and bathe our skin in pure waters. Meaning: we can focus our thoughts, guide our words and clean up our act.
Once scrubbed enough that light can pass through, we await the moment when the core awakens.
This is what Moses told his people on their last day together: "The hidden things belong to G‑d. But the obvious is for us and our children forever, to do what needs to be done."
Based on letters and talks of the Rebbe, Rabbi M. M. Schneerson 
