The Rebbe blesses the recipient for a kosher and joyous Pesach and urges increased influence on others in holiness. He highlights Pesach as the beginning of geirus and true freedom—from the yetzer hara—and notes that eating matzah strengthens emunah. A kuntres is enclosed, emphasizing that the physical nourishment of Pesach deepens faith.

https://www.torahrecordings.com/rebbe/004_igros_kodesh/nissan/985