Here, the Alter Rebbe explains how to have ahavas olam, eternal love. The general definition of
ahavas olam, is a love that it’s based on one’s understanding of the greatness of G-d, that is, His Creatorship, Kingship, etc. Since it is a love based on understanding, there are two (basic) ramifications:
1. It is limited, like the mind from where the love was born and the subject which was contemplated (existence).
a. Subject to change, for better or for worse.
When one contemplates with the “mind’s eye” how the G-dly energy which exist-ifies everything, one will be moved to a tremendous longing, yearning, desire, thirst for G-d. English doesn’t do it justice.
That’s why ahavas olam is called that: because olam, which means eternal, also means world and shares the root of the word hellem (concealment). This hisbonenus (contemplation) is centered around visualizing existence (the world) as it is and specifically in its relationship with G-dliness (not G-d who cannot be limited) as a veil. Ahavas olam is also called ahava zuta, or “small” love.
Likkutei Torah, parshas Eikev.