[יו"ד כסלו תשי"ח]
...אינו כותב כלל אודות פעולותיו בהפצת המעינות. ואם מתרשל בזה, הרי לכאורה, אין פלא מה שעניניו הפרטים מתנהגים בכבדות, שהרי הא בהא תליא.
B"H, 10 Kislev 5718.
He does not write at all about his activities in spreading the wellsprings. And if he is being negligent in this, then apparently it is no wonder that his personal matters are proceeding sluggishly, for one thing depends on the other.
Summary
The Rebbe teaches that one's personal success is directly connected to their efforts in spreading Chassidus. Neglecting this mission can lead to stagnation in other areas of life.