The Rebbe instructs that the individual be urged—repeatedly and clearly—to put on tefillin daily (except on Shabbat and Yom Tov), even briefly and even if delayed until later in the day. Emphasis is placed on the mitzvah's unique power to safeguard and prolong life, regardless of the person’s general religious observance.
https://www.torahrecordings.com/rebbe/004_igros_kodesh/iyar/1026