The letter urges dismissing fears of sorcery, strengthening bitachon in Divine providence, and focusing on practical avodah: checking tefillin and mezuzos, daily tzedakah, Tehillim, Torah memorization, proper self-discipline, chinuch of Jewish children, and meaningful participation in Chassidic farbrengens that lead to real change.
https://www.torahrecordings.com/rebbe/igroskodesh/016/003/5942