To love G-d, your G-d, to obey Him, and to cleave to Him, for He is your life and your length of days, to dwell in the land that G-d swore to your forefathers – to Abraham, Isaac, and Jacob – that He would give them.
Deut. 30:20
Realizing that “He is your life,” i.e., that G-d is the force within us that keeps us alive and gives us our zest for living, leads us to love Him. This love replaces the self-love that constitutes our inborn motivation to keep living and improving our lives.
But beyond this, the Torah is telling us here that it is possible for us to love G-d so much that this love becomes our very life, that we live off this love. Loving G-d enables us to cling to Him constantly, and clinging to Him constantly infuses our lives with infinite vitality and purpose.
— Daily Wisdom 3