The Medrash this week portrays the quid pro quo of our relationship with Hashem.
He who gives us life says "My light (Torah / Mitzvos) is in your hands as your light (Neshama) is in My hands! Guard My light which in your hands and I will guard your light which is in My hands!"
The promise of Shlomo Hamelech in Koheles "Whomever performs a Mitzvah will know no evil". For example we might think when we give Tzedakah we diminish our recourses, while in truth we lose nothing but only stand to gain. So too with all Mitzvos, Hashem promises, if we guard His Torah and perform His Mitzvos, He will protect us and insure our welfare and prosperity.